John 8:51-59 (NRSVCE)
Very truly, I tell you, whoever keeps my word will never see death.” The Jews said to him, “Now we know that you have a demon. Abraham died, and so did the prophets; yet you say, ‘Whoever keeps my word will never taste death.’ Are you greater than our father Abraham, who died? The prophets also died. Who do you claim to be?” Jesus answered, “If I glorify myself, my glory is nothing. It is my Father who glorifies me, he of whom you say, ‘He is our God,’ though you do not know him. But I know him; if I would say that I do not know him, I would be a liar like you. But I do know him and I keep his word. Your ancestor Abraham rejoiced that he would see my day; he saw it and was glad.” Then the Jews said to him, “You are not yet fifty years old, and have you seen Abraham?” Jesus said to them, “Very truly, I tell 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.
“Very truly, I tell you, before Abraham was, I am.” We remember here the words Moses heard come from the burning bush. Moses asks what God’s name is. He receives the response “I am who I am.” (Exodus 3:14) And now Jesus repeats the same. So what does it mean when God says to us “I am”?
Perhaps the easiest approach to this would be to consider the question “What are you?” If I were to say this to you, you would respond “I am a human.” If I were to ask this of an animal (and if animals could speak), they would respond “I am a cat” or “I am a dugong.” The answer to this always describes the kind of thing it is, or rather the kind of being it is. God’s answer to this question seems, at first, nonsensical. “What kind of being are you?” to which He responds “I am.” It is not His response which is nonsensical, but the question itself.
Everything in creation is a kind of being. We all “have” being, if we can put it that way. And everything that exists only does so because God created it. Everything only “is” because God wills it “be.” God is the source of everything that “is.” God is the source of all being. What that means is that God is not a “being” in the sense that you and I are “beings.” God does not “exist” in the same sense that we do. We exist contingently, meaning we are wholly dependent on God for our existence. God, on the other hand, exists necessarily—He could not not exist. That’s why He says to Moses “I am who I am.” He is what makes existence possible, giving “being” to His creation so that His creation can exist. This is why His response is as it is. “I am” emphasizes that God is not merely another kind of being, like a frog or even a demigod. He is being itself, the source of being for all things that exist.
The Jews understood this. They knew the tale of Moses very well, and they knew what the implications of God’s response were. This is why they are so outraged when Jesus says this of himself. It’s not because Jesus is claiming to be incredibly old, having seen Abraham, and it’s not because Jesus might be a time traveler. The Jews also knew that the only time travelers are Doc Brown and his trusty sidekick Marty McFly. And also Biff that one time, but that was still because of Doc and Marty. They were outraged because Jesus is claiming to be that necessary being. He is claiming to be “being.” They know immediately that Jesus is telling them he is God. This is scandalous! They immediately try to stone him for his blasphemy!
But it is true! The Father, the Son, and the Holy Spirit are the three persons of the one God who is the source of all being. The “I am!” It is why Jesus is able to say “whoever keeps my word will never see death.” Only God could promise this, because it is only God who has power over death.