In ancient times God was very anthropomorphic. He walked in the Garden "in the breezy part of the day".
He talked to man.
He was suprised by events.
He asked questions as though he needed information.
He was emotional and spontaneous. Angry at Adam and Eve and cursing the serpent one minute and warning Cain the next.
It was all kind of like a High School performance of a stilted play.
As we go from man's first very personable encounters with a tangible God and fast forward through the years, we find God is fading, fading, fading.
It hit me that as man became more sophisticated and less childlike and naive the stories about God had to be a bit more palatable. The High School Play had to become more off-Broadway.
When we get to Israel in Egypt and Moses leading the Jews through the Red Seas it is like a performance of Phantom of the Opera or Cats!
Big Production Values, set pieces, special effects: Plagues, miracles!! "My god is bigger than your god!"
But, God fades..fades..fades...
By the time of Malachi, God is an offstage voice. And then...silence.
By the time of the Christian Greek scriptures only Jesus seems to be able to hear Jehovah's offstage whisper.
The success of Alexander the Great brought Greek drama and science and logic to the Jews and they couldn't handle the ancient fables anymore without a grain of salt.
The Romans, largely, were becoming more sophisticated too. Belief in the old gods was largely ritual and regarded as a kind of "good luck charm" to ward off bad luck.
An actual person: The Emperor became the only real god for all practical purposes.
Arguments over who Jesus is/was devolved down to various opinions.
Under Paul the demi-god status of Jesus seems to have been set forth largely as the only acceptable and competitive alternative to old Judaism and current pagan Emperor status.
The split between the Catholic Church of Rome and the Orthodox Church of Constantinople is pretty much a debate over the science of the substance of God. (Homousias) God had faded into the definition of an undefinable conceptual leftover of Platonic philosophy!!
I remember the day I first thought about this. It became clear to me that children can accept a lot of fantastic detailed events in their bedtime stories which become less and less acceptable as they grow and mature. Belief in Santa Claus becomes an intellectual problem to tackle and solve until disbelief is certain.
The Disappearance of God is a function of the gradual sophistication of man's intellect.
Religion remains because of the strong and inveterate attachment we have emotionally to the bonding of childhood when anything was possible.
Santa and God are only kept alive when we replay the entire scenario for our children and vicariously experience the wonder and miracle of fantasy through them.