While he clung to Peter and John, all the people, utterly astounded, ran together to them in the portico called Solomon's. And when Peter saw it he addressed the people: “Men of Israel, why do you wonder at this, or why do you stare at us, as though by our own power or piety we have made him walk? The God of Abraham, the God of Isaac, and the God of Jacob, the God of our fathers, glorified his servant Jesus, whom you delivered over and denied in the presence of Pilate, when he had decided to release him. But you denied the Holy and Righteous One, and asked for a murderer to be granted to you, and you killed the Author of life, whom God raised from the dead. To this we are witnesses. And his name—by faith in his name—has made this man strong whom you see and know, and the faith that is through Jesus has given the man this perfect health in the presence of you all.
“And now, brothers, I know that you acted in ignorance, as did also your rulers. But what God foretold by the mouth of all the prophets, that his Christ would suffer, he thus fulfilled. Repent therefore, and turn back, that your sins may be blotted out, that times of refreshing may come from the presence of the Lord, and that he may send the Christ appointed for you, Jesus, whom heaven must receive until the time for restoring all the things about which God spoke by the mouth of his holy prophets long ago.
by: Jerry Johnson.
Throughout the Book of Acts, we find examples of the apostles challenging their hearers to repent and turn to God. If we simply present verses like John 3:16 without emphasizing the necessity of a change of mind concerning sin and rejection of Christ, we do not do justice to the full Gospel message. In this passage, Peter challenged Jewish religious people who may not have thought they needed to repent. At least four times (see also 2:38, 17:30, and 20:21) Peter and Paul connected saving faith with repentance. They are two sides of the same coin; you cannot have one without the other.