Apostles to the Jews
Unlike Paul, Peter and the others were designated to be the apostles to the Jews.
On the contrary, they saw that I had been entrusted with the task of preaching the gospel to the Gentiles, just as Peter had been to the Jews. For God, who was at work in the ministry of Peter as an apostle to the Jews, was also at work in my ministry as an apostle to the Gentiles. James, Peter and John, those reputed to be pillars, gave me and Barnabas the right hand of fellowship when they recognized the grace given to me. They agreed that we should go to the Gentiles, and they to the Jews. (Galatians 2:7-9)
A New Source for Forgiveness
The apostles were carrying the message that the Jews were to have one final washing (baptism) with water. The story of the woman at the well explains that there was a water that satisfied after one drink leaving her never to be thirsty again. Similarly, the baptism that the apostles were giving was demonstrating a washing that would never need to be repeated again.
"Therefore let all Israel be assured of this: God has made this Jesus, whom you crucified, both Lord and Christ." When the people heard this, they were cut to the heart and said to Peter and the other apostles, "Brothers, what shall we do?" Peter replied, "Repent and be baptized, every one of you, in the name of Jesus Christ for the forgiveness of your sins. (Acts 2:36-38)
They heard was about a new way of salvation which was and continues to be Jesus Christ and Him alone!
And you will receive the gift of the Holy Spirit. The promise is for you and your children and for all who are far off - for all whom the Lord our God will call." With many other words he warned them; and he pleaded with them, "Save yourselves from this corrupt generation." Those who accepted his message were baptized, and about three thousand were added to their number that day. (Acts 2:38-41)
Sacrifices and offerings used to be the normal way to achieve forgiveness. It was called atonement and it only covered over sins until the following year. Jesus was to be their new source of forgiveness. His way is called propitiation which means to completely satisfy the payment for sin. It doesn't just temporarily cover it over anymore!
