In the beginning, between 2500 BC - 1000 BC, God was presented in the flashiest forms: Global warming. Burning bushes. Absolute reign over man, demon and weather. Infinite wealth. Oceanic division. Etc.
It worked in convincing man for as long as they remembered. As soon as generations elapsed…the prophets had to start over again.
Then almost simultaneously, between 500BC and 30AD, Plato, Buddha, Confucius and Jesus agreed, "Okay, since flashy miracles don't seem to work in enlightening man, let us limit the scope of miracles to man himself."
So they taught that man is God's miracle. His birth, life, thoughts and death are all miracles.
But man was still miserable. The more they were taught how to be happy, how to think and believe, the more miserable they became. The deeper they held on to religion, the more miserable they became. The Middle Ages, the crusades, the Inferno.
Finally, the masters said, "You know, let's just take away all crystallized signs of miracles. Let man find the magic in brevity, in what flows."
And they left man with each other's actions: what they said and did to one another as the remaining sign of God's presence on Earth.