What Should You Do When You Realize You’ve Been Wrong?

Peter's first sermon, repentance, and the question that brings change closer to home.

By Pastor John Erickson

I remember the first sermon I ever preached.

I was in tenth grade, speaking to a little youth group. I prepared and practiced for about three weeks. I studied. I was nervous, but I gave it everything I had.

Afterward, I walked up to a friend and asked the question every new preacher probably shouldn't ask: 'What did you think?'

He said, 'Man, you know a lot about sheep.'

Not quite the response I was hoping for.

The sermon was on Psalm 23. I had been reading a shepherd's account of the psalm and how sheep need care and guidance. Apparently the sheep information made an impression.

Just perhaps not the impression I had in mind.

When we come to Acts 2, we encounter Peter delivering one of the most consequential sermons in Christian history. And unlike my first attempt, the response is pretty extraordinary.

A Man Who Had Failed Is Now Preaching

Remember who Peter is.

He followed Jesus closely. He saw miracles. He declared his loyalty. And then, when the pressure came, he denied knowing him.

A short time later, Peter stands before a crowd in Jerusalem and speaks openly about Jesus' death and resurrection.

Something has changed.

The Holy Spirit has been poured out. Peter no longer sounds like someone hiding from the possibility that people might associate him with Jesus.

And what does he preach?

He explains that the extraordinary events at Pentecost are connected to God's promise in Joel to pour out his Spirit. He tells the story of Jesus, including his crucifixion and resurrection, and proclaims that Jesus is Lord and Messiah.

This is not a motivational speech about how the crowd should try harder to be good people.

It's a call to reckon with Jesus.

"What Shall We Do?"

Acts 2:37 says the listeners were cut to the heart. They turn to Peter and the other apostles and ask what they should do.

I think that's an incredibly honest question.

You realize something is wrong. Maybe you've hurt somebody. Maybe you've built your life around an assumption that turns out to be false. Maybe you've spent years resisting the very thing God has been trying to show you.

At that moment, there are a couple of options.

You can defend yourself. Explain why you did what you did. Find somebody else to blame. Or you can ask, 'What should I do now?'

Peter tells them to repent and be baptized in the name of Jesus Christ for the forgiveness of sins, and he promises the gift of the Holy Spirit.

Repentance means turning. It isn't simply feeling bad long enough that we think we've paid for our mistake. It's responding to God's grace by changing direction.

And Peter knows something about needing that kind of grace.

Salvation Is the Beginning of a Relationship

Sometimes we talk about salvation as if it were a box you check once and then never think about again.

Have you been saved? Great. Done. Next item on the list.

But the New Testament describes a relationship with the living Jesus. There is a decisive beginning, yes. And there is also a lifetime of learning to follow him.

Imagine talking to a newly married person and asking how they're growing in their relationship. What if they answered, 'Growing? We're already married. I achieved the goal.'

I think most of us would see the problem.

A relationship isn't a certificate you stick in a drawer. You keep showing up. You learn. You grow. You make mistakes. You seek forgiveness and reconciliation.

The gospel is good news not only for the first moment we believe but for every day we need to return to Jesus.

Change Begins Closer to Home Than We Think

Near the end of the sermon, Peter urges his listeners to be rescued from what he calls a corrupt generation.

I can read a line like that and immediately begin thinking about all the problems in society. The broken institutions. The people behaving badly. Everything that's wrong out there.

And those problems matter.

When I was preparing this sermon, Peter's words about a corrupt generation stayed with me. I could feel helpless looking at the world, convinced things were bent out of shape and unsure what one person could possibly do.

But I couldn't keep asking that question as though I stood outside the problem.

But Peter's answer directs us first toward repentance.

In other words, before I can spend all my energy trying to straighten out everybody else, I need to let Jesus deal with me.

I think about how easy it is to be drawn into cycles of retaliation. You hurt me, so I hurt you. Then you hurt me worse, so I find a way to get even. We become part of the very brokenness we say we oppose.

Jesus gives us another way to live.

We may not be able to solve every problem in the world. But we can stop defending the sin in our own hearts. We can ask forgiveness. We can receive grace. We can begin treating people differently.

Maybe the most useful question we could ask isn't merely, 'What's wrong with the world?'

Maybe it is, 'Lord, what needs to change in me?'

That's where Peter's sermon begins to become our own story.