"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." NIV translation
Now that the crowd is wondering how the crippled beggar was healed, Peter puts the focus on Jesus and their role in his crucifixion. Peter points out that the One who healed the beggar is the same one that they turned over to be crucified. Can you imagine the thoughts going through the minds of the people in the crowd? You know that feeling that you get in the pit of your stomach when you realize that you really messed something up, that is what I picture the crowd coming to realize and the sinking feeling they must have felt.
"You disowned the Holy and Righteous One and asked that a murderer be released to you. You killed the author of life, but God raised him from the dead. We are witnesses of this. NIV translation
Peter is still showing the crowd of Jews what they have done. He points out that they even chose a murderer over Jesus. Then, he moves on to tell them that God raised that same Jesus from the dead. We may think that these verses are harsh but how many times do we choose things other than serving Jesus each day?
Peter goes on to tell them that John and him are witnesses of the fact that Jesus was raised from the dead. At that time, there were many stories going around as to why the tomb was empty. There were rumors that the body was stolen by the disciples as well as others but John and Peter testify to the fact that Jesus had risen.
"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 given this complete healing to him, as you can all see." NIV translation
It is hard to believe until you see with your own eyes and that is basically what Peter is telling the crowd here. He reminds them that they have seen the beggar and know him. He then explains how the man that they knew as a crippled beggar was standing there before them. Peter tells them that the power only comes through faith in Jesus Christ.
"Now, brothers, I know that you acted in ignorance, as did your leaders. But this is how God fulfilled what he had foretold through all the prophets, saying that his Christ would suffer." NIV translation
After pointing out how the crowd had been a party to the crucifixion of Jesus, he now strikes a more conciliatory tone by stating that he knows that it was done in ignorance. He then goes on to point out that God knew it was going to happen and in fact Jesus came knowing that he would be rejected. Isn't it awesome to know that God even uses our ignorance to fulfill his purpose?