[ZNPaaneah]

“Fellow Israelites, why does this surprise you? Why do you stare at us as if by our own power or godliness we had made this man walk? 13 The God of Abraham, Isaac and Jacob, the God of our fathers, has glorified his servant Jesus. You handed him over to be killed, and you disowned him before Pilate, though he had decided to let him go. 14 You disowned the Holy and Righteous One and asked that a murderer be released to you. 15 You killed the author of life, but God raised him from the dead. We are witnesses of this. 16 By faith in the name of Jesus, this man whom you see and know was made strong. It is Jesus’ name and the faith that comes through him that has completely healed him, as you can all see.

Compare this verse with James 5:16

Jesus name is "the righteous person" the faith that comes through him is the faith that operated in Peter to be one with the Lord.

17 “Now, fellow Israelites, I know that you acted in ignorance, as did your leaders. 18 But this is how God fulfilled what he had foretold through all the prophets, saying that his Messiah would suffer. 19 Repent, then, and turn to God, so that your sins may be wiped out, that times of refreshing may come from the Lord, 20 and that he may send the Messiah, who has been appointed for you—even Jesus. 21 Heaven must receive him until the time comes for God to restore everything, as he promised long ago through his holy prophets.

Peter has forgiven them because "they acted in ignorance". They didn't repent, instead he is now calling them to repent so that their sins may be wiped out. Peter forgave them prior to them repenting and their sins being wiped out.