Acts 2:37-38

Now when they heard this they were stung (cut) to the heart, and they said to Peter and the rest of the apostles (special messengers), Brethren, what shall we do? And Peter answered them, Repent (change your views and purpose to accept the will of God in your inner selves instead of rejecting it) and be baptized, every one of you, in the name of Jesus Christ for the forgiveness of and release from your sins; and you shall receive the gift of the Holy Spirit.