The ancient Jewish tradition is that God gave his name to us in a very odd sort of non-name: he who is. The development, of course, has been substantial since. But the core idea was actually expressed well by St. Anselm in his famous proof, the general idea that God is being itself.
It isn't easy for JWs and XJWs to grasp this idea, raised as we were on a very simplistic idea of -- to borrow the term -- a sky wizard. But, within the Christian thinking, God isn't a sort of being, really. He isn't the greatest thing among a universe filled with other things. He's that than which nothing greater can be conceived.
To see how far from the Sky Wizard idea that is, you just have to work through the statement. The Sky Wizard and my sofa together must be greater than the Sky Wizard. So, in this understanding, the Sky Wizard isn't God. God is the thing that is not made greater by addition and is, therefore, being itself. Hence the non-name.
It's also probably wrong to ascribe attributes to God, the way we did when we were JWs. We used to say that God has main attributes of love, justice, wisdom, and power. But this is thinking about it wrongly, I'd say. God isn't a thing to which attributes are added. St. John speaks of God as being love, not as an entity that has lots of love or that shows love, but love itself.
That's an enormous distance from caricatures offered by atheists and, to be fair, lots of Christians.