Acts 2:37-42

Now when they heard this, they were pierced to the heart, and said to Peter and the rest of the apostles, “Brethren, what shall we do?” 38 Peter said to them, “Repent, and each of you be baptized in the name of Jesus Christ for the forgiveness of your sins; and you will receive the gift of the Holy Spirit. 39 “For the promise is for you and your children and for all who are far off, as many as the Lord our God will call to Himself.” 40 And with many other words he solemnly testified and kept on exhorting them, saying, “Be saved from this perverse generation!” 41 So then, those who had received his word were baptized; and that day there were added about three thousand souls. 42 They were continually devoting themselves to the apostles’ teaching and to fellowship, to the breaking of bread and to prayer.

Here we have an immediate response by the people to Peter’s previous sermon—particularly when he said that they nailed Christ to the cross. They no doubt were convicted by the Holy Spirit who just came down to them.

When they asked Peter what to do, he said that they should repent and be baptized. And I take it that Peter did not separate repentance from baptism. He was not telling them to just be dunked under the water as an act of obedience; but to act out the meaning of baptism—that they would be buried and resurrected with Christ; hence, that they would be forgiven of their sins and receive the gift of the Holy Spirit. It may be that Peter explained to them more thoroughly what baptism means.

“The promise” (in verse 39) I think is both the receiving of the Holy Spirit and their salvation; for they could not be saved apart from the Holy Spirit.

The three thousand souls that were saved and added to the church is something hard to fathom. Where did they come from? Those in the upper room (120 persons) must have immediately gone out to evangelize others and then brought them together. How did it all happen so quickly? No doubt it was a revival that was spread quickly by the Holy Spirit as well as by all those who witnessed the Holy Spirit’s coming and Peter’s message.