Mercy: A Matter of Life and Death

God is a God of mercy and justice. He shows staggering mercy to people who don’t deserve it because that’s just who He is. He forgives sin because that’s just what He does.

Chris Hutchison on September 3, 2023
Mercy: A Matter of Life and Death
September 3, 2023

Mercy: A Matter of Life and Death

Passage: Psalm 51
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Imagine that you’re being led away to die. It’s a public death—an execution—and the town has lined up to watch. Among the crowds you can see the faces of your family. At the end of the road is the city square where you glimpse the shape of a platform, with a tall stake, surrounded by bundles of branches, where you know a fire will be lit which will burn you to death.

In half an hour, your life will be over.

What do you say? What words come off of your mouth?

For many Christians who lived during the time of the Reformation, this picture I’ve just painted was not imaginary. Hundreds of Christians were burned at the stake for simply believing the gospel.

And for many of those Christians, do you know what words were on their lips as they were led away and tied to the stake and the fires were lit and they were unable to say any more?

Psalm 51. So many stories are recorded of martyrs saying Psalm 51 as they died that some have called this the “Martyr’s Psalm.”

Why would an ancient prayer of confession from an Israelite king guilty of adultery and murder be the last words on the mouths of Christian martyrs two and a half thousand years later?

I hope that by the end of our time here this morning, you’ll have an answer to that question. And perhaps, because of what we do here this morning, when your last hour comes, the words of Psalm 51 might be the words coming from your mouth. That’s a tall order but I think we’ll find Psalm 51 is able to live up to its reputation.


1. Background

Let’s begin, as we always want to begin with a Psalm, by considering the background to the Psalm itself. Remember that the headings to these Psalms, in small caps, are a part of the biblical text. This one says “To the choirmaster. A Psalm of David, when Nathan the prophet went to him, after he had gone in to Bathsheba.”

Many of you will be familiar with the story. After years on the run, David finally got settled in Jerusalem, and enjoyed a stretch of victories over his enemies. Things were finally going well for him.

But one spring, instead of going out to battle with his men, David sent them away without him, and stayed behind in Jerusalem, maybe to enjoy a little well-deserved R&R. And late one afternoon, he gets off his couch, goes for a walk on the roof of his house—which would have been at the highest point in the city—and he looks down to see the wife of one of his elite warriors having a bath on her roof (2 Sam 11:3, 23:39).

And he knows that her husband is miles away. And he’s the king. He can do whatever he wants.

So, overcome with lust, he sends for Bathsheba and sleeps with her. And she becomes pregnant. And to cover up his sin, David arranges for her husband—one of his loyal servants who had faithfully served him through so many battles—to be murdered. And then he takes Bathsheba, makes her his own wife, and she bears him a son.

You can read all about this in 2 Samuel 11. And that chapter ends with these words, “The thing that David had done displeased the Lord” (2 Samuel 11:27). Literally, those words could be translated, “The matter that David did was evil in the eyes of the Lord.” 1Crossway Bibles, The ESV Study Bible (Wheaton, IL: Crossway Bibles, 2008), 560.

But the Lord came after David. He sent Nathan the prophet to tell David a parable about a rich man who stole a lamb from his poor neighbour, and when David reacted in outrage, Nathan told him, “You are the man!” (2 Samuel 12:7). Nathan said more, and after hearing it all, David responded like this: “I have sinned against the Lord” (2 Samuel 12:13).

Now what did David mean by that? Was that just a quick, “I’m sorry,” just to get the prophet off of his back? Or did David really understand what he had done? Psalm 51 tells us. Here we see David’s heart laid bare in repentance and confession to the Lord.

Let’s follow along as we hear how David responded to the Lord after Nathan’s confrontation.

2. Mercy (vv. 1-2)

Our first stop is verses 1 and 2, which in many ways are the summary of the entire Psalm. “Have mercy on me, O God, according to your steadfast love; according to your abundant mercy blot out my transgressions. Wash me thoroughly from my iniquity, and cleanse me from my sin!” (Psalm 51:1–2).

David knows what he deserves for his crimes against Bathsheba and Uriah: he deserves the death penalty. So David begins by begging God for mercy. He’s begging God for His very life.

Notice the different words he uses here for his sin. “Transgressions… iniquity… sin.” Notice also the four main requests he makes of God in these verses.

First, that God would have mercy on him—on other words, be kind to him instead of giving him what he deserves. Second, that God would blot out his transgressions—wipe them out of his record book. Third, that God would wash him throughly from his iniquity, and fourth, closely related, that he would be cleansed from his sin.

Notice how multi-dimensional sin is. Sin makes us dirty. Sin is recorded by God in the heavenly record. And sin provokes God’s judgement. All of these aspects need to be dealt with if David is going to escape with his life.

And so he begs for mercy.

But notice how David begs for mercy. Notice the basis for his request. Why should God forgive David? After all he had done, why should he be let off the hook? What would give David the idea that mercy is even an option?

“Have mercy on my, O God, according to your steadfast love; according to your abundant mercy blot out my transgressions” (v. 1).

You can’t miss this: David does not point to anything in himself for a reason for why he should receive mercy. “Have mercy on me, because I won’t do it again. Have mercy on me, because I’m really really sorry and I’ll make up for it. Have mercy on me, because I was really tired that day and my other wives were all having bad days. Have mercy on me, because I’ve done so much good for you over the years.”

No, David knows that what he did was wrong, deserving of death, and his only hope is that God is a God who shows mercy.

The language David uses here is intentional. Both the language for his sin, and the language for God’s mercy. It all comes from Exodus 34, when God proclaims His name to Moses.

“The Lord passed before him and proclaimed, ‘The Lord, the Lord, a God merciful and gracious, slow to anger, and abounding in steadfast love and faithfulness, keeping steadfast love for thousands, forgiving iniquity and transgression and sin, but who will by no means clear the guilty, visiting the iniquity of the fathers on the children and the children’s children, to the third and the fourth generation’” (Exodus 34:6–7).

God is a God of mercy and justice. He shows staggering mercy to people who don’t deserve it just because that’s who He is. He forgives sin because that’s just what He does.

But He’s not Santa Claus, either. He also judges the guilty. And David knows that he is guilty. He deserves judgement. He can’t assume that God will just let him off the hook.

So he grabs ahold of God’s name, and says “please be merciful to me, not because I deserve it, but because that’s just who you are. Please forgive me, not because I deserve it, but because that’s just what you do. Please be kind to me, not because I deserve it, but just because you show steadfast love to people. That’s who you are.”

3. Sin (vv. 3-5)

Now that’s just the introduction to the Psalm. In the next section, verses 3-6, is where David confesses his sin to the Lord. He doesn’t try to hide or whitewash what he’s done. “For I know my transgressions, and my sin is ever before me” he says in verse 3. David’s been stuffing down a guilty conscience for months. Nathan just helped David admit to what he knew all along.

“Against you, you only have I sinned and done what is evil in your sight” says verse 4. Isn’t that astounding? After all, didn’t David sin against a lot of people? Didn’t he sin against Bathsheba and Uriah and Joab and his whole nation when he broke their trust? Of course. But what his words draw attention to here is that in each and every one of those sins, the main person he sinned against was the Lord.

David sinned against the Lord because those people he hurt were God’s creations, made in His image. David sinned against the Lord because it was God who had put him in his position of authority and gave him every good gift. So when David abused his power and hurt the people he was supposed to protect, when he reached out to take even more, he was slapping God in the face.

And David sinned against the Lord because the Lord had specifically told Israel not to do those things David did. Just think of how many of the Ten Commandments he broke. That’s what Nathan the prophet said: “Why have you despised the word of the Lord, to do what is evil in his sight?” (2 Samuel 12:9).

Every sin anybody ever does is ultimately sin against God. And so David admits, in the rest of verse 4, that whatever God says against him, and whatever God does to judge him, would be fair and right and just. God would be just to judge David because all his sin was against God.

We can’t miss that David isn’t blaming anybody else for his sin. Bathsheba probably shouldn’t have been bathing on the roof. Joab probably shouldn’t have obeyed David’s order to have Uriah killed. But none of that excused David. He was responsible for himself, and he alone was to blame for what he did. Don’t miss how David takes full responsibility for himself when he says “Against you, and you only, have I sinned.” There’s no pointing fingers here.

In verse 5 David recognizes that his sin goes all the way back to his birth. “Behold, I was brought forth in iniquity, and in sin did my mother conceive me” (Psalm 51:5). He was born a sinner. He was a sinner in his mother’s womb. And I don’t think we should see him blaming his sin on this. It’s better to understand this as a lament at just how total his sinful condition is.

Stepping back, we can see how in this whole section, verses 3-5, David admits that what happened, no matter who else was involved or who else got hurt, was between him and God. He owns his responsibility for his sin even as he laments how powerless he is to escape or rescue himself from it.

4. Salvation (vv. 6-12)

And so next David asks God to save him. And what’s so important is that the focus here is not actually that David would be saved from the death penalty. The focus here is that David would be rescued from the presence and the power of sin in his own heart.

David knows, just like Jesus would teach centuries later, that adultery and every other sin starts in our hearts (Matthew 5:27). And so in these next verses David asks for God to restore his heart. To save him from the inside out.

He begins by acknowledging that this is what God wants: “Behold, you delight in truth in the inward being, and you teach me wisdom in the secret heart” (Psalm 51:6). God wants purity and wisdom deep inside.

So, verse 7: “Purge me with hyssop, and I shall be clean; wash me, and I shall be whiter than snow. Let me hear joy and gladness; let the bones that you have broken rejoice. Hide your face from my sins, and blot out all my iniquities” (Psalm 51:7–9).

The language of “purging” and “washing” probably points to the rituals at the temple, where hyssop and water and blood were used to make people and objects “clean” before the Lord. But David knows that those rituals pointed to a deeper reality—the need to be clean in our hearts. And that’s what he’s asking for here. To be clean inside, to have his joy restored, and yes, to have God wipe away the record of his sins.

Verse 10: “Create in me a clean heart, O God, and renew a right spirit within me.” This word for “create” here is the word used consistently throughout the Old Testament to talk about God’s creation out of nothing. David can’t change his own heart any more than he can say “let there be light.” He needs God to do an act of creation, calling forth a clean heart where one did not previously exist.

Verse 11: “Cast me not away from your presence, and take not your Holy Spirit from me” (Psalm 51:11). That’s what David deserved to have happen. He deserved to be thrown away from God’s people, unable to join them to worship in the temple. In fact he deserved to be thrown away from the company of the living and to be cast down to the grave itself.

And he deserved to have the Holy Spirit taken from him. The point of this verse isn’t whether or not it’s possible for the Holy Spirit to be taken from someone, the point is that this is what he deserved. After what he did, ait would have been just and fair for the Holy Spirit to leave David completely. So he begs for God to not abandon him, but instead to, verse 12, “Restore to me the joy of your salvation, and uphold me with a willing spirit” (Psalm 51:12). He wants a spirit that is willing and happy to obey the Lord, and which rejoices in God’s salvation, and once again He knows that only God can give that to him.

5. Worship (vv. 13-19)

Now we get to the last movement in the Psalm, where we find out where this is all headed. Why does David want to be cleaned and given a new heart? Is it just so that he doesn’t have to die? Is it just so that he can save face and keep being the king? Is it so that he can stop feeling so lousy?

The answer is none of those things. The real reason why David asks to be saved is so that God can be worshipped by David and others like him.

Listen to verses 13-15: “Then I will teach transgressors your ways, and sinners will return to you. Deliver me from bloodguiltiness, O God, O God of my salvation, and my tongue will sing aloud of your righteousness. O Lord, open my lips, and my mouth will declare your praise” (Psalm 51:13–15).

That’s where this is headed. God is glorified when He saves sinners. And that’s what he’s after. Just like last week—“Save me so I can praise you!”

We have to keep this picture in mind when we get to verse 16, which says “For you will not delight in sacrifice, or I would give it; you will not be pleased with a burnt offering” (Psalm 51:16). The idea here is not that sacrifices and burnt offerings mean nothing, because verse 19 looks forward to bringing these offerings.

Think about it this way: for months, David had been going through the motions while hiding his sin. For months he wold have been taking part in the regular offerings. And what he’s understanding here in verse 16 is that bringing an offering to God, when your heart was far from God, was meaningless.

God is not worshipped by songs and gifts and offerings alone. God is worshipped by hearts that rejoice to trust and obey him. And that’s the worship David is finally bringing in verse 17: “The sacrifices of God are a broken spirit; a broken and contrite heart, O God, you will not despise.”

Verse 18 looks beyond himself to the city: “Do good to Zion in your good pleasure; build up the walls of Jerusalem” (Psalm 51:18). David knows that his sin affected the nation. As he seeks forgiveness for himself, he is seeking blessing for his city and his people.

And as God accepts the repentance of his people, and does good to Jerusalem, then God will be honoured by the acceptable worship in the temple. Verse 19: “then will you delight in right sacrifices, in burnt offerings and whole burnt offerings; then bulls will be offered on your altar” (Psalm 51:19).

And that’s where Psalm 51 ends: with the hope and expectation that God will hear his prayer, will save him, will spare his life, and will be worshipped well into the future by David and other repentant sinners whom David has helped lead back to the Lord.

And we know David’s prayer was answered. Even though there was discipline and consequences, God showed David so much more kindness than he deserved. And it was through Bathsheba that the Messiah would come who would one day make this forgiveness even possible in the first place.


But before we jump ahead too far, we want to pause and ask what it meant for Israel to sing this Psalm together before Jesus came. This song was in Israel’s hymnbook, and we have record that they sung Psalm 51 every year on the Day of Atonement, the day when a priest would enter the most holy place of the temple to offer the blood of a bull and a goat to make atonement for Israel’s sin.

As Israel sung this song, they would be reminded that sin lurked within each of them. If David could sin in this way, so could any of them.

As Israel sung this song, they would be reminded that, even if they hadn’t murdered or committed adultery, even their “small” sins were sins against God. This Psalm would keep their consciences tender, reminding them that they needed mercy just as much as David did.

Singing Psalm 51 would remind them that, if God forgave David, He could forgive them when they repented as well. God’s grace and steadfast love was for them.

The last verses of the Psalm in particular would remind them that their lives were interwoven together, and that their sins affected not just them but the nation. They each needed to get right with God for the sake of their people.

By singing this Psalm on the Day of Atonement, they would be reminded that blood must be shed to pay for their sins. But also, by singing this song on the Day of Atonement year after year after year, they would also be reminded that this blood of bulls and goats could never really and finally deal with their sin. More animals always needed to be killed. More blood always needed to be shed. The new hearts they prayed for, the new hearts God had promised to give them (Ezekiel 36:26) always seemed out of arm’s reach.


And that’s why this Psalm points a line straight to Jesus. The Messiah, traced through Bathsheba’s line, fulfills Psalm 51. Not because these words were ever true of Him. Jesus never needed to ask forgiveness for anything. But Jesus made it possible for the Father to say “yes” to every person in all time who ever prayed these words.

God could have mercy on David because, and everybody else who ever prayed these words, because on the real Day of Atonement, Jesus would die on the cross for their adultery and murder and lust and hatred and selfishness.

And the risen Son of David, enthroned at the Father’s right hand, would send His Spirit to give His people the new, born-again hearts that they so desperately needed.

The mercy that Psalm 51 begs for was bought and paid for by Jesus, who today offers it to all who would ask.


And that brings us to us. On this side of Calvary, we can see that Psalm 51 is about the gospel. Psalm 51 is about being saved by God’s grace and mercy alone through faith alone in Christ alone.

“Nothing in my hand I bring, simply to the cross I cling. Naked, come to thee for dress. Helpless, look to thee for grace. Foul I to the fountain fly. Wash me saviour, or I die!”

We bring nothing but our cries for mercy, and God saves because He delights to save. Maybe there’s some of you here today who need to pray Psalm 51 for the first time. “Have mercy on me, O God.” And you can rest assured that He will. He cannot say no. He promised, “whoever comes to me I will never cast out” (John 6:37). So bring your nothing and feel the Father’s welcome today.

1) Ongoing Confession

Now let’s take a step past that point. What about those of us who have come to Jesus, and have received His mercy. Does Psalm 51 have any place on our lips? Any place in our worship?

And the answer is yes, because the New Testament shows us that confessing our sin is a normal part of the ongoing Christian life. How did Jesus teach us to pray? “Forgive us our debts, as we also have forgiven our debtors” (Matthew 6:12). James 5:16 says “Confess your sins to one another and pray for one another.” 1 John 1:8 & 9 says, “If we say we have no sin, we deceive ourselves, and the truth is not in us. If we confess our sins, he is faithful and just to forgive us our sins and to cleanse us from all unrighteousness.”

Jesus paid for our forgiveness once and for all, but He wants us to come to the Father regularly to seek that forgiveness. Which means that confession is an ongoing reality in our lives. Which means that Psalm 51 is for us.

2) Genuine Holiness

But as I thought about this truth this week, I had a serious question. How does this reality of ongoing confession fit with what the New Testament teaches us about genuine holiness? Now that we’ve been given new hearts through the Holy Spirit, we shouldn’t stay stuck at the same place we were when we first came to him. We can’t let sin reign over us (Romans 6:12, 14).

So do you get the tension here? If we’ve been born again, why would we need to ever pray Psalm 51 again? Couldn’t Psalm 51 actually encourage us to stay stuck, wallowing in sin, and never making any progress in being more like Jesus?

This is an important question, and I’d suggest there’s at least three answers to it. The first is that there is a difference between progress and perfection. Yes, we must grow to be like Jesus. But that process won’t be complete until we’re with Him in glory.

1 John captures this tension so well. Don’t say you’re sinless (1 John 1:8-10), but also, you can’t keep on sinning (1 John 3:3-6).

I think of this in the context of marriage. I love my wife with a love that is real and has grown so much since we were first married. Do I love her perfectly? No. Do I still have many opportunities to say sorry and ask her forgiveness? Yes. But just because my love isn’t perfect doesn’t mean it isn’t real and hasn’t grown substantially.

So, holiness should be real and growing even if it won’t be perfect until heaven.

The second answer is that the more a Christian grows in Christlikeness, the more sensitive their consciences are to things that didn’t bother them before. As they beat one sin, they see another one they hadn’t noticed before.

I’ve seen this again and again when guys break free from porn. One of the first things they notice is a bunch of other sins, like impatience or anger, that they hadn’t noticed before. Killing one sin helped them see others that they now need to fight.

A third answer is that the longer someone walks with Christ, the more vulnerable they are to certain temptations, specifically towards spiritual pride. Remember Paul, who after knowing Jesus so well and even being caught up to heaven itself, needed a thorn in his flesh to keep him from being conceited (2 Corinthians 12:7).

You’d think that just knowing Jesus so well and for so long would make it impossible to sin, but our flesh is so sneaky that the opposite is true. The more that we look like Jesus, the more we can be tempted to believe that we’re so awesome and so much better than everybody else. Which means we’ll have fresh opportunities to repent as long as we’re here on earth.

There’s more than we can say, but taken together I hope we can see that real growth in holiness and real confession of sin will always go together for God’s people.

3) Repentant Worship

Now if all of this is true, and if Psalm 51 was an important part of Israel’s worship, then I think we can see that confession of sin should be a part of our worship together.

There are many ways that confession and repentance are already woven in to our worship services together.

We regularly sing songs that confess our sinfulness and celebrate the way that Jesus has rescued us. When one of the elders leads the pastoral prayer, almost every Sunday they speak about our need for forgiveness and the good news that God has provided this forgiveness in Jesus. We give regular opportunities as the service starts and ends to be quiet and talk to God about whatever is on your heart, which should often includes confession. Every month we share in the Lord’s supper where we celebrate the mercy of God offered at Calvary. And in our preaching we don’t shy away from addressing sin and calling us to repent.

I do wonder, though, if there’s still room for us to grow in this way. Throughout church history, many churches have been even more explicit than we are in giving space for confession. In many churches throughout history it was common each week for the people to, out loud, confess their sin to the Lord, often using the words right out of Psalm 51. And then the pastor leading the service will respond by assuring the people of God’s mercy and forgiveness in Christ.

I was at a church this summer that practiced this, and it was really wonderful. Standing with a group of people and asking for God’s mercy together really works against that whole “everybody here has it all together” thing that we talked about last week.

And it leads to joy. Psalm 51 shows us that confession does not leave us wallowing in bad feelings.

There’s some Christians who think that way. They think being mature means  feeling guilty all the time, and that feeling a certain low-grade guilt is a sign of being spiritual.

It’s not. It’s actually sinful, because living in guilt is a refusal to believe Jesus’ words that “it is finished.” When the Lord convicts you of a sin—through His word, through His Spirit, through a brother or sister, through a sermon—you confess it, maybe praying Psalm 51, and you believe that you are forgiven for Jesus’ sake, and then you go walk with a clean conscience to go put that sin to death—not to earn peace with God, but because you already have it.

And so when we repent and confess our sins to God together, we can be assured that He has forgiven us, and that causes the joyful praise of the redeemed to come welling up and spilling over. His mercy opens our lips, and our mouth praises Him for being so extraordinarily kind to us.

And that’s why I believe Psalm 51 was on the lips of so many martyrs as they stared down death. They knew that in just minutes they’d be in the presence of God, and that in and of themselves, they were all in David’s shoes, deserving nothing but His judgment. No amount of good works they had ever done could outweigh their sin and rescue them from hell.

But the words of Psalm 51 pointed their hearts towards the free mercy of God, helping them hope in His steadfast love and cast themselves upon His grace.

As they prayed “Have mercy on me, O God, according to your steadfast love,” they knew that He had. As they prayed “according to your abundant mercy blot out my transgressions,” they knew that He had. As they prayed “wash me thoroughly from my iniquity and cleanse me from my sin,” they knew that He had.

And this morning I encourage us to take up Psalm 51. Maybe, in the future, our services will include a more regular time of more confession of sin together. But today, take every chance you’re offered to throw yourself on God’s mercy. What if you memorized even just the first two verses? Let Psalm 51 lead you by the hand through repentance and confession straight into the heart of a Father who has promised to receive all who come to Him in faith.