What's the meaning of this...

12And 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? 13The 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. 14But you denied the Holy and Righteous One, and asked for a murderer to be granted to you, 15and you killed the Author of life, whom God raised from the dead. To this we are witnesses. 16And 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.

17“And now, brothers, I know that you acted in ignorance, as did also your rulers. 18But what God foretold by the mouth of all the prophets, that his Christ would suffer, he thus fulfilled. 19Repent therefore, and turn back, that your sins may be blotted out, 20that times of refreshing may come from the presence of the Lord, and that he may send the Christ appointed for you, Jesus, 21whom heaven must receive until the time for restoring all the things about which God spoke by the mouth of his holy prophets long ago. 22Moses said, ‘The Lord God will raise up for you a prophet like me from your brothers. You shall listen to him in whatever he tells you. 23And it shall be that every soul who does not listen to that prophet shall be destroyed from the people.’ 24And all the prophets who have spoken, from Samuel and those who came after him, also proclaimed these days. 25You are the sons of the prophets and of the covenant that God made with your fathers, saying to Abraham, ‘And in your offspring shall all the families of the earth be blessed.’ 26God, having raised up his servant, sent him to you first, to bless you by turning every one of you from your wickedness.”