“And when Peter saw it, he answered unto the people, Ye men of Israel, why marvel ye at this? or why look ye so earnestly on us, as though by our own power or holiness we had made this man to walk?”
The God of Abraham, Isaac and Jacob, the God of our ancestors, 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. — Peter grounds his appeal in covenant tradition (God of Abraham, Isaac, and Jacob), establishing continuity between the OT God and the present God acting through Jesus. Jesus is identified as God's servant (pais theou, servant/child, an OT title connoting obedience and suffering, cf. Isaiah 52-53). The charge of handing Jesus over to death and disowning him before Pilate is bold; the audience's corporate guilt is stated directly but opens the possibility of repentance.