John 8 - "I am"
In one of the several "I am" in the book of John, Jesus clearly states that I am the light of the world. Jesus came not only to redeem man but to show us what God is like. He them defends his statement by showing that his testimony about himself has two witnesses, he and his father. That is what was required by the law. Yet they did not believe who he was and therefore did not believe in his father.
Being a descendent of Abraham does not save anyone. To be good standing with God is to obey the word, acknowledge that we are sinners and accept Jesus as savior.