One of the more famous quotes is,
"I have never seen the slightest scientific proof of the religious ideas of heaven and hell, of future life for individuals, or of a personal God. So far as religion of the day is concerned, it is a damned fake… Religion is all bunk."This quote is not taken out of context. He really did not believe in Heaven or Hell, the afterlife, or a personal god, but that does not mean he did not believe in any God. Much like Thomas Jefferson, Edison was a theist, even though he had some serious disagreements with the religions of his day.
In an October 2, 1910, interview in the New York Times Magazine, Edison also stated:
"Nature is what we know. We do not know the gods of religions. And nature is not kind, or merciful, or loving. If God made me — the fabled God of the three qualities of which I spoke: mercy, kindness, love — He also made the fish I catch and eat. And where do His mercy, kindness, and love for that fish come in? No; nature made us — nature did it all — not the gods of the religions."This actually caused a bit of an uproar, with public accusations of Edison being an atheist. He never allowed himself to get wrapped up in the public drama, but he wrote the following privately in a letter:
"You have misunderstood the whole article, because you jumped to the conclusion that it denies the existence of God. There is no such denial, what you call God I call Nature, the Supreme intelligence that rules matter. All the article states is that it is doubtful in my opinion if our intelligence or soul or whatever one may call it lives hereafter as an entity or disperses back again from whence it came, scattered amongst the cells of which we are made."Edison specifically states that he believes in a Supreme Intelligence, but not the god of modern religions. Nature was Edison's god, and he considered it a sentient force. An Intelligence. He was a pantheist, believing that everything is part of an all-encompassing immanent God, or that the Universe (or Nature) and God (or divinity) are identical.
Edison put it even more simply when he wrote on a piece of stationary from his office,
"I believe in the existence of a Supreme Intelligence pervading the Universe."In addition, his family also testified regarding his belief in a Supreme Being:
"He never was an atheist. Although he subscribed to no orthodox creed, no one who knew him could have doubted his belief in and reverence for a Supreme Intelligence, and his whole life, in which the ideal of honest, loving service to his fellowman was predominant, indicated faithfully those two commandments wherein lies `all the law and all the prophets."