Here's a topic to make one burn out a few braincells!
It seems to me that the concept of infinite regression, with no original cause, is self-defeating. I think Aristotle concluded a few interesting truths about God without necessarily knowing him. He concluded, for instance that God is eternal, one, perfect, and the uncaused cause.
Of course, in Stephen Hawkings' books, he constructs time as an infinite 3 dimmensional model, which would make asking questions like "what existed before the beginning of time?" or "What exists outseid the boundaries of the universe?" meaningless.
Time can apparently not exist without space, but I don't know if space can exist without time. Perhaps the eternal, atemporal structure of time and space is a glimpse into the mind of God.
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"And lo, the beast looked upon the face of beauty. And beauty stayed his hand. And from that day on, he was as one dead."