“...Let all the house of Israel therefore know for certain that God has made him both Lord and Christ, this Jesus whom you crucified.” 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?” And 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. For the promise is for you and your children and for all who are far off, everyone whom the Lord our God calls to himself.” And with many other words he bore witness and continued to exhort them, saying, “Save yourselves from this crooked generation.” So those who received his word were baptized, and there were added that day about three thousand souls. - Acts 2:36-41
Jesus has been raised from the dead. He has made multiple appearances to the disciples. For 40 days, he taught them about the kingdom of God and gave them their mission (Acts 1:8). Then, he ascended to heaven, back to the Father from where He rules and reigns. Ten days later, the Holy Spirit falls upon them and Peter preaches to the masses that centers on Jesus being the long-awaited, Scripture-promised Messiah, whom the people (through the agency of the Roman government) crucified.
What follows in 2:36-41 is a record of what happened when the Spirit took the word proclaimed and brought it to bear on the hearers. First, there was an internal work. They were cut to the heart. Conversion and new life in Christ is not something that works from the outside in. It starts at the heart and then works its way out. This is because the heart is deceitful and wicked. It is out of the heart that evil deeds flow. So, change must begin inside us. The gospel is not mere behavior modification.
Second, the internal work needs an external manifestation. The internal converting work of the Spirit leads the people to cry out, “What are we to do?” They intuit that the changed heart will lead to a changed life. This is not works righteousness. Notice internal cutting of the heart that the Spirit does is first, then works flow out of the transformation that God has wrought. Works are not wrong or bad. It just matters that they are in the proper sequence. This was James’ concern in his epistle, that some would claim conversion and new life but produce no fruit or works that evidenced such a change.
Third, this change is summarized by repentance. To repent is not only to turn away from our sins, though that is certainly included. It is to turn all of our lives towards Christ and center them on Him. Sin must be excluded because by definition it is in opposition to Him. But repentance also means we give up all of our previous plans and ways of doing things or at least hold them with open hands. It means that while we still value our relationships, those relationships have to be ordered in light of Jesus. Our repentance means we cannot have any other love that is greater than or takes precedence over our love for our Lord. The symbol or sign of this commitment to orient all of our lives toward Christ is baptism.
Finally, this new life in Christ is the fulfillment of promises. All that happened in the life, death, and resurrection of Jesus Christ was to bring to pass all that God committed Himself to do. But this fulfillment was not intended to be limited to one generation. God’s purpose and plan has always had the future generations in view. Thus, the promise is for our children. And it was never meant to be limited to one people or ethnic group. So, even those who are far off (the Gentiles) are included. No surprise, given that God had told Abram that He was blessing Abram so that through him, all the nations would be blessed.
Saints, let us rejoice and give thanks that our conversion and new life in Christ rests ultimately on God having done an internal act to give us a new heart, on Him continuing that transforming work by His Spirit now, and in His faithfulness to see this new life reach its full flowering.
