The idea of a god concept has existed since the beginning of time in virtually all cultures. It is used to explain what men do not understand. Historically, the god-concept has been a tool of the powerful for exploiting the weak and willing. As the line goes in Shakespeare's play, Julius Caesar, Caesar would not be so willing to be a wolf if the Romans were not so willing to be sheep. A god, any god, would not exist if believers did not grant existence to him. God is a creation of man, not man a creation of God. My understanding of God is that he exists in the minds of those who choose for Him to exist.
"Pay no attention to the man behind the curtain," said the wizard as Dorothy, the Tin Man, the Lion, and the Scarecrow uncovered his scam. There is no wizard in Oz, just as there is no omnipotent wizard controlling the universe. There is as much evidence supporting the existence of Santa Clause or UFOs, as there is the existence of God. Certainly, there is belief, conjecture, and desire, but none of these abstractions is supported by a single fact.
There are those who claim the wisest scientific minds of modern times, Darrow, Einstein, Hawking believe in God, but this is incorrect. Each of these scientists recognizes the universe as a spectacular and magnificent entity of the highest order, but does not attribute its creation to God. Einstein and Hawking acquiesce to the idea that this "order" is worthy of a kind of godliness, if that is the name one wants to apply to it, but neither accepts the concept of a God-creator, God-the-father, God-the-intervener. Darrow disavowed God altogether as he matured.
My understanding of god is that man created him out of the need to explain what we can not readily explain. To that extent, he exists in our minds, hearts, and theories as a construct, but not necessarily as anything tangible or rational. Having a God to believe in fulfills our need to extend our lives beyond one lifetime, to generate "after life." We are a creative lot, we humans. Our ability to scheme, devise, and create is apparently boundless. If necessity is the mother of invention, historically we humans need and invent "gods-du-jour." We have done so since the beginning of time. The modern (in reality, ancient) God of Christianity, Judaism, and Islam shares many of our human characteristics. It is hard to accept that he passed those traits on to us. It is more logical that in our creating him, we endowed him with our own traits.
I've always been intrigued by the "jealous God," "the angry God," "the vengeful God," and the "wrathful God" as he is referred to in the ancient texts. Wow! Talk about a range of human fallibility! The wrath of God being like a two-edged sword takes his human-like characteristics to a level befitting early Bible cultures needing to dominate their neighbors. It is despotic in nature, not god-like. Humans who strive for peace, harmony, and collaborative problem solving have recognized for years that these negative "god-like" qualities are counter productive in peaceful society. When we are confronted with a God who is angry, jealous, vengeful, wrathful we accept that he has that right to be so because he is, after all, God. This God is much like the husband in an abusive relationship. Because he brings home a paycheck, of sorts, we accept his right to be angry, jealous, vengeful. This god is a tool of his creators. He has been used historically and is still being used to wage war, to dominate, to control.
How do we explain a God who designs children with crippling birth defects when (according to tradition) he has the power to create each child to be perfect? Some of us are fortunate enough to have been born without basic imperfections. Others are not so fortunate. The randomness of this process sounds way too much like a god who is either not paying attention or who has a terribly twisted sense of justice. In our need to justify his actions we explain these events by saying he works in mysterious ways, that these children are born this way to teach lessons, or that the parents have sinned. We swallow the inconsistencies of his behavior, irrationally, because we cannot accept the randomness of these anomalies. We claim the existence of god because doing so makes the tragedies of life more palatable to us.
It isn't enough to explain God's shortcomings with, "God works in mysterious ways." That is both illogical and irrational. Our theories rationalizing his actions need to measure up, to hold water. We need facts to support them. God is more like us than like an omnipotent, omniscient, all-powerful force. The only rational theory regarding God is that we created Him to fit our need to have Him. To that degree, I understand the He does exist.
There is proof that "something" exists, a universe, the earth, people, a life force, but how it exits, how it was created, the extent of it's power, and why it exists eludes us. Irrationally, we attribute this existence to a god-concept because, rationally, it suits us to do so. I understand that humans want and need a God, as Dorothy needed a wizard in Oz at the end of the yellow brick road. God is just a man behind the curtains in our churches and in our minds. It makes us feel good to believe in magic and fantasy. Sometimes we call this belief God.