Genesis because it tells us whether the covenant was with Ishmael or Isaac:
"Abraham fell facedown; he laughed and said to himself, "Will a son be born to a man a hundred years old? Will Sarah bear a child at the age of ninety? And Abraham said to God, "If only Ishmael might live under your blessing! Then God said, "Yes, but your wife Sarah will bear you a son, and you will call him Isaac. I will establish my covenant with him as an everlasting covenant for his descendants after him. And as for Ishmael, I have heard you: I will surely bless him; I will make him fruitful and will greatly increase his numbers. He will be the father of twelve rulers, and I will make him into a great nation. But my covenant I will establish with Isaac, whom Sarah will bear to you by this time next year. When he had finished speaking with Abraham, God went up from him."** (Genesis 17:17-22).**
And the Gospel according to John because there are some important quotes for Jesus, such as:
(John 8:58 ):
*"Jesus said to them, “Truly, truly, I say to you, before Abraham was born, I am.” *
(John 6:38):
“For I have come down from heaven not to do my will but to do the will of him who sent me.”
(John 8:23):
"But he continued, “You are from below; I am from above. You are of this world; I am not of this world.”