One of the most convincing proofs of the truth of Christianity is the existence of the church itself. The church came about through the witness of a group of disciples who had been utterly transformed by their encounter with the risen Christ. There is no transformation more striking than what happened in the life of Peter. Having an encounter with the risen Christ and empowered by the Holy Spirit who came to fill His church at Pentecost, Peter helps us understand who Jesus is and what He expects of us.

Who Is Jesus Christ?
Much has been made of the fact that it was wishy-washy Peter who stood up and boldly proclaimed to a hostile, skeptical crowd what was happening on the first day of Pentecost. When the tongues of fire separated and landed on the heads of the disciples and the multinational crowd heard the gospel in their own native languages, it was Peter who answered the nonsense of those who said the disciples had had too much wine. He boldly told the crowd the basic facts of Jesus' life and ministry. In verse 36, he gets to the essence of what it means to be a follower of Jesus: who Jesus is and what He expects from us.

Peter used two words to tell us who Jesus is: Lord and Christ. We could use these words and assume everyone knows their meanings and not really ponder their significance. If you do a word study of Lord and look at all the ways it is used in Scripture, you learn some very basic things. Jesus Christ is God the Son, incarnate in human flesh. As such, He is to be obeyed. He is to be heeded. He is to be our Teacher. The Christian life is one of learning to acknowledge the supremacy of Jesus Christ in all things and submitting to Him.

Not only is he Lord, but He is Christ. He is Messiah. He is the One promised throughout all the ages, and He is the One who alone is sufficient to save us from our sins. We can be saved from judgment, condemnation and purposelessness by Him and Him alone.

What Does He Expect from Us?
As Peter preached, the anointing of the Holy Spirit upon him was so strong that the listening crowd was cut to their hearts and cried out, "What shall we do?" What a wonderful moment it is for any preacher when a listener hears from God and is convicted by His Spirit through our preaching, and they have no other recourse than to cry out to Him, asking, "What shall I do?"

That question can be answered in different ways by each listener, depending on where he or she is in his or her spiritual journey. Peter gave two clear words of instruction as to what comes first: Repent, and be baptized. As you're cut to the heart and convicted by the preaching of the Word, the first response is to repent.

Repentance is a gift from God that enables us to be made right with Him. I like to present it this way: It is simply saying to Him, "God, I'm sorry I've been living for myself rather than You. Please forgive me. If You'll give me grace and strength, I want to live the rest of my life for You. I want to serve You above all else."

Peter also said, "Be baptized in the name of Jesus Christ." We understand baptism to be that way of identifying with Jesus Christ, of giving witness to the world that our old selves have died and been buried with Christ, and new creations have been born again by the power of the Holy Spirit.

The promise for the one who acknowledges the Lordship of Jesus Christ and comes to Him in repentance and obedience is empowered by His Holy Spirit to live a life greater than anything we ever could have dared dream or imagine.