The God of Abraham, Isaac and Jacob
God wants Moses to do something, but Moses doesn't want to do it. So, Moses comes up with a list of excuses, the first of which is: I can't; I'm disqualified; I yam what I yam. God responds, "Ultimately, it doesn't matter who you are. What really matters is that I will be with you."
So, Moses' next question is, "Well...who are you?"
Now, if I were God -- and that's a dangerous way to begin any sentence -- I would rattle off a list of things...mostly things I do. "I'm the one who created all this stuff. I'm the one who lit the sun and flung the stars around the universe and dug the grand canyon with the little finger of my left hand. I'm the one who made you, and I'm the one who could kill you right here and now. So, pay attention!"
But that's not what God does. First, he pronounces the unpronouncable name. Then -- and here's the really bizarre part -- he defines himself in relationship to humans. "I am the God of Abraham, the God of Isaac, the God of Jacob."
First, and foremost, the Bible defines God -- not categorically -- but personally and relationally. Rather than running through a bullet-list of concepts and actions, rather than giving his resume and experience, God says I'm the one who was in relationship with Abraham, Isaac and Jacob. Now I want to be in a relationship with you and the rest of those folks in Egyptian slavery. I desire a relationship with people -- always have, always will.
This is so contrary to how we're often taught to think of God. Yes, he is self-sufficient. No, he doesn't need us in some kind of "I'm-incomplete-and-can't-live-without-you" sort of way. He is differentiated enough for his life to continue whether we choose to engage him or not.
And yet...he has no problem changing his name for our sake. That is part of who he is -- part of the I AM what I AM that he communicates here in Exodus 3. He is the ineffible God, the God who is self-sufficient and self-sustaining, the God of the burning bush who comes in search of men and women who will take him by the hand and walk in relationship with him.