Marked as Belonging to Christ | Acts 2:37–41
Introduction
We are going to be in Acts 2, verses 37-41, this morning – please join me there.
Today is a really good day for us as a church. Here’s why: we get to celebrate the ordinance of baptism. But I want us to understand that what we are doing is not simply observing a “religious ceremony.” We are not just watching someone “take the next step” in some vague spiritual journey. What we are witnessing is what God does when He saves sinners by grace through faith in Jesus Christ.
When God saves someone, He does not leave that work hidden. He marks it. He names it. He makes it visible. That is what baptism is.
And baptism is worship. It is the gospel made visible. It is the Word of God preached, not only to our ears, but to our eyes.
And yet, because baptism is familiar to many of us, it can quietly lose its weight. We know the routine and the language. We know when the person goes under the water and comes back up. We even know when to clap. And that familiarity can sometimes trick us into thinking we understand something more deeply than we actually do.
So today, as we witness baptism together, we want to slow down. We want to be sure we can answer this question: what is God saying to us in baptism?
And this is not just what God is saying to the people being baptized today. But to the whole church. And even to those who may still be wondering what it would mean to follow Christ.
Let’s read these verses together, then I’ll pray, and then we’ll jump into what God left us here.
Read Acts 2: 37-41.
Prayer.
Point 1: The Gospel Creates a People Before It Marks Them (Acts 2:37)
Acts chapter 2 takes place on the day of Pentecost. The Spirit has been poured out. The apostles are preaching boldly. Peter has just stood up and proclaimed the gospel. He told the crowd who Jesus is, what they did to him, and what God did in raising Him from the dead.
Christianity is a hearing religion before it is a seeing religion. Before there is anything visible, there is the Word of God proclaimed. Before there is baptism, there is gospel preaching. Before there is a public sign, there is an inward work of grace.
This matters because we live in a culture that loves visible moments and these defining experiences. We like ceremonies that feel weighty and meaningful. And if we’re not careful, we can quietly load baptism with expectations it was never meant to carry.
Baptism does not awaken dead hearts or produce repentance. No, the Gospel – and only the Gospel – does that.
And those people Peter preached to had just heard the Gospel presented to them. And then we read this in verse 37:
Now when they heard this they were cut to the heart…
That phrase matters. It tells us that these are not people with some mild, passing interest. This is not general curiosity. This is conviction. This is the Spirit of God taking the Word of God and driving it home into the hearts of sinners.
Only after that do they ask,
“Brothers, what shall we do?”
Hear the conviction in that. It is the cry of people who know they have encountered the truth and cannot remain the same. That cry – what shall we do – is the sound of grace at work.
This is why Peter’s response begins where it does. He calls them to repent and to be baptized – not so that they might receive grace, but because grace has already begun its work in them.
Baptism never replaces the gospel. It rests on it.
This is why the apostle Paul can say in 1 Corinthians that Christ did not send him primarily to baptize, but to preach the gospel. Paul is not minimizing baptism. He is protecting the gospel from being overshadowed. The gospel creates the reality; baptism proclaims it.
What we are celebrating today did not begin at the baptistry. It began at the cross, where Jesus bore the sins of His people. It was secured at the empty tomb, where He triumphed over sin and death. And it was applied personally when the Spirit of God opened hearts to believe.
Baptism stands downstream from grace. It is not the source of new life – it is the sign that new life has already begun.
The Gospel creates a people before it marks them.
Point 2: Baptism Is God’s Public Mark of Belonging (Acts 2:38 – 39)
Peter answers the crowd’s question with a simple but weighty command:
Repent and be baptized every one of you in the name of Jesus Christ for the forgiveness of your sins, and you will receive the gift of the Holy Spirit.
Forgiveness does not come from the water – it comes from Christ. Baptism is the outward sign that accompanies repentance and faith in Him.
And that phrase – in the name of Jesus Christ – is not filler. It tells us what baptism means.
To be baptized in someone’s name is to be identified with them. It is to come under their authority. It is to belong to them.
And that brings us to the central truth we need to hear very clearly this morning: In baptism, God is saying to us: “This person belongs to Me.”
That sentence reflects a Biblical reality. In baptism, God is not primarily highlighting our sincerity, our maturity, or our spiritual progress. He is making a declaration. He is marking someone publicly as belonging to Christ. Baptism is not mainly about our story – it is about God’s claim.
This is where we often need to be re–taught, because many of us have learned to think of baptism almost exclusively as our testimony. And there is truth there. Those being baptized today are publicly confessing Christ. They are saying, “I trust Jesus. I follow Jesus. I belong to Jesus.”
But Scripture pushes us deeper.
If baptism were only our testimony, then its meaning would rise and fall with our strength. With our clarity. With our consistency. And if we’re honest, that would make baptism fragile – because we are fragile.
The Bible presents baptism as something sturdier than that.
Romans 6 tells us that baptism proclaims our union with Christ in His death and resurrection. Galatians 3 tells us that in baptism we are clothed with Christ. Colossians 2 tells us that baptism points to our burial and resurrection with Him through faith.
The water does not create those realities – Christ does. But baptism is how God visibly proclaims what He has done invisibly.
This is why baptism matters when faith feels small, assurance wavers, and emotions fluctuate.
Because baptism is not anchored in how tightly we hold on to God, but in how firmly God has claimed us in Christ.
At the same time, Scripture is equally clear about what baptism is not. Let’s be very clear:
Baptism does not save you. Jesus saves you.
Baptism does not justify you. Faith alone justifies you.
Baptism does not guarantee perseverance. God’s grace sustains you.
But baptism still matters. It is still holy. It is still God speaking.
It is a sign. And signs matter because they point beyond themselves. In baptism, God is preaching the gospel in visible form.
When someone is baptized, God is not saying, “Look how strong this person’s faith is.” He is saying, “Look how sufficient My Son is.”
And that is why baptism is good news. It takes our eyes off ourselves and fixes them again on Christ. It declares belonging – not earned, not achieved, but graciously given.
And Peter grounds all of this in something deeper still. He says in verse 39,
39 For the promise is for you and for your children and for all who are far off
That word promise matters. Baptism is not grounded in human resolve, emotional sincerity, or spiritual momentum. It is grounded in the promise of God. And that promise is not narrow or fragile – it is expansive and gracious. It reaches those standing in front of Peter that day. It reaches generations that follow. It reaches those who are far off – far off geographically, far off morally, far off spiritually.
But notice how Peter ends the sentence:
everyone whom the Lord our God calls to himself.”
The promise is wide, but it is never vague. It is always applied by God’s calling grace.
Baptism, then, is not a claim that someone has earned belonging. It is a declaration that God has called them, that the gospel promise has reached them, and that they now belong to Christ by grace through faith.
That is why baptism is such a strong word of assurance. It does not rest on how confident we feel about God – it rests on the fact that God keeps His promises. In baptism, God is saying, “This promise applies here. This promise applies now. This person belongs to Me.”
And that declaration stands firmer than feelings, steadier than circumstances, and truer than any story we could ever tell about ourselves.
Baptism is God’s public mark of belonging.
Point 3: The Joy and Weight of Belonging to God (Acts 2:40)
When we hear the language of belonging, our instincts are often warm – and that’s a right way to fee;. Belonging sounds like welcome. And the gospel truly offers that kind of belonging. In Christ, sinners are welcomed, forgiven, and brought near.
But Scripture never lets belonging become casual. When God says, “You belong to Me,” He is not only offering comfort – He is making a claim. Belonging to God means being claimed by God. It means coming under His gracious authority, and grace always precedes obedience, but grace never cancels obedience.
This is why baptism is both joyful and serious.
In Acts 2, belonging is celebrated. Thousands are baptized. They are added to the church. Joy is everywhere. But as the story unfolds in Acts, we also see that belonging to God’s people carries weight. In Acts 5, when Ananias and Sapphira pretend to belong while holding back their hearts, the result is sobering. God is teaching His church something vital: belonging to Him is not a game.
Baptism, then, is not only a celebration – it is a declaration of allegiance. It says, “I am no longer my own. I belong to Christ.” And that belonging reshapes everything. It reshapes how we think about sin, how we think about obedience, and even how we think about our lives.
But here is the good news: the weight of belonging does not crush us – it steadies us.
When God claims someone as His own, He does not do so harshly. He does so as a loving Father who delights in His children. The same God who says, “You belong to Me,” also says, “I will never leave you nor forsake you.”
That is why belonging to Christ is the safest place in the world to be.
In baptism, God is not placing a burden on someone’s shoulders that they must carry alone. He is placing His name on them and promising His presence. He is not saying, “Now prove yourself.” He is saying, “Now walk with Me.”
This is where joy and seriousness meet. Baptism is joyful because it declares grace. Baptism is serious because grace transforms. And when we hold those together, baptism becomes neither sentimental nor severe – it becomes what Scripture intends it to be: a holy, hopeful declaration that sinners now belong to a faithful God.
Luke goes on to tell us in verse 40 that Peter did not stop with invitation alone.
40 And with many other words he bore witness and continued to exhort them, saying, “Save yourselves from this crooked generation.”
That language might sound strange to our ears, but Peter is not preaching self–salvation. He is calling for a decisive break in allegiance.
In other words, baptism does not only say, “You belong to Christ.” It also says, “You no longer belong to this age.” To belong to Jesus is to be transferred – out of one kingdom and into another. Out of one way of life and into a new one. Grace rescues us, and that rescue always involves separation from what once defined us.
This is why belonging is joyful and weighty. Baptism marks not just forgiveness, but a new identity. A new loyalty. A new direction. Peter’s exhortation reminds us that grace is never passive. When God claims someone as His own, He is not merely comforting them – He is calling them into a new way of life in Christ and shaped by His kingdom.
There is both joy and weight in belonging to God.
Point 4: Baptism Incorporates Believers into the Visible Church (Acts 2:41)
And then verse 41 tells us something that can be easy to just move past quickly, but it is important. After those who received Peter’s word were baptized, Luke says this in verse 41:
41 So those who received his word were baptized, and there were added that day about three thousand souls.
That word “added” there is doing more work than we might realize. Added implies a people. Added implies recognition. Added implies belonging to something visible and defined.
Baptism did not leave these new believers floating in private spirituality. They were not baptized and then sent off to figure out their faith on their own. They were baptized and then added – incorporated – into the life of the church.
This is a consistent pattern in the New Testament. To belong to Christ is to belong to His body. Paul later says this in 1 Corinthians 12:13:
For in one Spirit we were all baptized into one body—Jews or Greeks, slaves or free—and all were made to drink of one Spirit.
[Main Points Slide]
Baptism is not only about vertical reconciliation with God; it is also about horizontal incorporation into God’s people.
And those words were spoken into a culture that prizes independence and personal choice. Being of ‘one body’ to ‘drink of one Spirit’ --- that was not the normal in any way. This was different. But isn’t that as true today? We live in a culture that prizes independence and personal choice. And being ‘one body’ to ‘drink of one Spirit’ --- well, that is different.
I think we sometimes fall into this trap of seeing faith as something intensely private – something that happens between me and God alone. But Scripture presents faith as personal without ever being private. The gospel saves individuals, yes – but it always saves them into a community.
This is why the New Testament does not recognize a category of Christian who belongs to Christ but has no meaningful relationship to the church. Baptism marks the boundary of visible belonging. It says, “This person is not only united to Christ by faith – they are now identified with His people.”
The church is where believers are known and loved. It is where they are taught and shepherded. It is where they are encouraged when faith feels weak and corrected when sin threatens to harden the heart.
This is also why baptism naturally connects to church membership. Membership does not create belonging – it recognizes it. Baptism declares, “This person belongs to Christ.” Membership says, “We recognize that belonging and commit to walking together in obedience and care.”
So when someone is baptized, the church is not merely witnessing an event – we are joyfully receiving a brother or sister. We are affirming their confession of faith. And we are committing ourselves, in love, to walk with them as fellow members of Christ’s body.
Baptism, then, is not just about the individual standing in the water. It is about the people standing around the water. It is about a church joyfully saying, “You belong here – because you belong to Christ.”
Application
Martin Luther, the German reformer, once famously said, “I am baptized.” Not because water saved him – but because baptism pointed him back to Christ. Baptism is something Christians return to again and again – not physically, but spiritually. Not to the water itself, but to the Christ it points us to. It reminds us who we are and whose we are.
For those baptized today: this is not the finish line. This is the starting line.
For those baptized long ago: remember whose name is on you.
For those who believe but have not been baptized: obedience flows from belonging.
For those who do not yet believe: look at the grace on display. This is the promise Christ offers.
Conclusion
The water you see today does not cleanse the conscience. But the blood of Christ does. And baptism points us again to the Savior who washes sinners clean, unites them to Himself, and gathers them into His church.
Today we rejoice – not in water, but in grace.
So back to our opening question: what is God saying to us in baptism? He is saying: “This person belongs to Me.”
And there are no better words a sinner could ever hear.
Let’s pray.
Prayer.