Three thousand people could point to that specific day when they repented, were baptized, and received forgiveness and the gift of the Holy Spirit. That first Pentecost was not only the dividing line of history; it was the dividing line in their lives.
“Let all the house of Israel therefore know for certain that God has made him both Lord and Christ, this Jesus whom you crucified.”
Acts 2:36
What Do We Do?
This certainty Peter is calling his listeners to, and calling us to, is not arrogant certainty. He’s calling us to the kind of certainty that leads us to humble trust, the kind of certainty that causes us to reevaluate what we’ve been putting our confidence in up to this point and to recognize that Jesus is worthy of our trust, worthy of our lives. This conclusion or certainty he’s calling his listeners to is, in one sense, a matter of the mind. Peter has made a clear case to be thought through and evaluated, contending that Jesus is the Christ as promised and prophesied in the Old Testament. But Peter is not merely calling for intellectual agreement. He’s calling for a personal response to the truth he has presented. Jesus is Lord. And because of that he should not, indeed he cannot, be resisted or ignored. The reality of the person of Jesus demands a response. And the group in the sound of Peter’s voice wants to know how to respond.
Now when they heard this they were cut to the heart, and said to Peter and the rest of the apostles, “Brothers, what shall we do?”
Acts 2:37
“Cut to the heart.” The reality of the identity and lordship of Jesus pierced into the deepest parts of the disciples’ minds, wills, and emotions. They were moved by this reality—so much so that they were willing to do whatever it took to respond rightly to this revelation. Peter was ready with an answer. He told them three things that they needed to do in response to their certainty that God has made Jesus both Lord and Christ:
Peter said to them, “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.”
Acts 2:38