John 8 begins with a sinful woman who was about to be stoned for adultery. Jesus last words to her was “Go and sin no more”. Jesus did not condemn her for the past but forgave and pointed to the future. The he got into an argument with the religious powers about his and their ancestry. They claimed to be descendants of Abraham, and they questioned the legitimacy of Jesus. Jesus answered “Before Abraham, I am”. Jesus claimed to be God. This was of course blasphemy, unless it is true.
Genesis 21 tells about the birth of Isaac and when Ishmael made fun of it, Sarah got angry and Hagar and Ismael were sent away to die in the desert, but God protected them. The chapter also features the treaty between Abraham and Abimelech at Beersheba.
In Genesis 22 Abraham was told by God to offer up his son Isaac to be sacrificed on Mount Moriah, the same mountain that Jesus was crucified on. Obeying God he did what he was told, but at the last moment God provided a substitute sacrifice in the form of a ram.