About fifty days after the death, burial, and resurrection of Jesus Christ, Jews from many different countries gathered in Jerusalem to celebrate the day of Pentecost, or the “Feast of Weeks,” as it was commonly known (Exodus 34:22; Numbers 28:26). Before this day, Jesus had “presented Himself alive after His suffering, by many convincing proofs, appearing to [the apostles] over a period of forty days and speaking of the things concerning the kingdom of God” (Acts 1:3, NASB).
Shortly before his acension to heaven, Jesus promised his apostles that they would receive power when the Holy Spirit came upon them and that they would be his witnesses “in Jerusalem and in all Judea and Samaria, and to the end of the earth” (Acts 1:8).
After the fulfillment of this promise (Acts 2:1-4), the apostle Peter was given the opportunity to preach the gospel to the many Jews in Jerusalem who had gathered to celebrate the Feast of Weeks. Toward the end of his discourse, Peter tells the multitude, “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).
In the verses that follow, we see that “…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…'” (Acts 2:37-38).
Acts 2:38 explicitly states that the purpose of baptism (or immersion in water) is “for the forgiveness of your sins.” This baptism is to be carried out “in the name of Jesus Christ” because it is the very baptism authorized or commanded by the Lord himself shortly before he ascended to heaven (Mark 16:15-16; Matthew 28:19). In accordance with what Peter told the multitude on the day of Pentecost in Acts 2, Ananias told Saul of Tarsus, “Why do you wait? Rise and be baptized and wash away your sins, calling on his name” (Acts 22:16).
One “calls on the name of the Lord” and is “saved” (Acts 2:21) when he/she is baptized for this purpose (Acts 2:38). About three thousand souls on the day of Pentecost called on the name of the Lord in this way (Acts 2:41) and, as a result, were “saved” (Acts 2:47). This is exactly why Peter says, “Baptism … now saves you … through the resurrection of Jesus Christ” (1 Peter 3:21). There is no miraculous power in the water! Baptism “saves … through the resurrection of Jesus Christ” when one obeys “in the name of Jesus Christ” (Acts 2:38), that is, in humble submission to his authority.