It’s quite a few verses but to get the full context we need read John 8:31-59.
In an oft quoted verse of scripture Jesus tells his followers “You will know the truth and the truth will set you free.” Many of us are familiar with these words even those who have not read the Gospels. But the audience that day asks how they can be set free, claiming they have never been enslaved to anyone. Let’s think about that claim. The defining moment of Jewish history is the Exodus from Egypt and the way they encountered God at Mount Sinai. They had served as slaves for hundreds of years in Egypt. The nation of Israel was taken into Babylonian captivity and later by the Assyrians. In Jesus’ day their land was a province of the Roman Empire. To claim they had never been enslaved to anyone was an exaggeration at best, but what Jesus really meant was that anyone who sins is a slave to sin. He really riles them up by telling them their father is not Abraham but the devil, and they do what their father does which is try to kill him. They will then claim they have only one father and that is God! Jesus says if that were so they would love him for he came from God, but instead they are the offspring of murdering Satan who is a liar and the father of lies. They accuse him of being a Samaritan and possessed by a demon, and it all comes to a head when Jesus tells them Abraham rejoiced to see them in his day.
So the Jews said to him, “You are not yet fifty years old, and have you seen Abraham? Jesus said to them, “Truly, truly, I say to you, before Abraham was, I am.” So they picked up stones to throw at him, but Jesus hid himself and went out of the temple.
He told them they were not the children of Abraham nor the children of God. He told they were the children of Satan and called them murderers and liars. But they didn’t lose their cool and try to stone him to death until he implied he was older than Abraham. So what’s really going on here?
The statement before Abraham was, I am implies that Abraham lived and died but that Jesus is eternal. But there is also more to it. Recall Moses’ conversation with God at the burning bush. He was told to say, to the Hebrews and before Pharaoh, “tell them I AM has sent you.” It is from this verse in ancient Hebrew we get the name YHWH (which we see sometimes as Yahweh or Jehovah). Jesus is using statements made by God to describe himself, possibly using the very name of God. It was ultimately his claim to be the Messiah and accusations of blasphemy that led to the crucifixion. Jesus did some things that only Jesus can do. His claim to be the Son of God sent from heaven would truly have been blasphemous… had he not been sent by God!