How did Peter use the Genesis covenant promises in his sermon about Jesus?
Peter claimed the Genesis covenant promises made to Abraham, Isaac, and Jacob, identifying the God of the fathers as the one who glorified His Son Jesus. He used those promises to address Israel, then accused them of delivering up and denying Jesus before Pilate when Pilate was determined to release Him.
Les explains that Peter is speaking to the nation of Israel. The names Abraham, Isaac, and Jacob immediately identify the Jewish people, because those three men marked the beginning of their nation. God had repeated the covenant promises almost word for word to Abraham, Isaac, and Jacob. To Abraham God promised to make of him a great nation and make his name great, and the end of that covenant was that through this man salvation would go to the ends of the earth. Les points out that Peter now claims those Genesis covenant promises, calling on the God of Abraham, Isaac, and Jacob, the God of our fathers, and declaring that He has glorified His Son Jesus. Peter then accuses Israel of delivering up and denying Jesus in Pilate's presence, even though Pilate was determined to let Him go.