Board Thread:Questions and Answers/@comment-5157293-20130324003807/@comment-1713281-20130324023119

(This is a bit of a long-winded response, so be prepared)

Religion in the Marvel universe, and all the cosmic, world-starting/world-ending implications that go along with it, is a highly fluid concept. This goes not only for the ancient religions that we would call lore in our universe (the Olympians of Graeco-Roman peoples, the Heliopians of Ancient Egypt, the Asgardians of the ancient Norse, the Amatsu-Kami, who are connected to Shinto), but also for the "contemporary" religions practiced by many believers today (like Yahweh and Satan from the Jewish and Christian belief systems).

Now, in a move likely designed to not offend readers by aligning themselves with any one religion, Marvel has taken the approach that no one religion, or god, or group of gods, is the one true answer. In the Marvel Universe, the "gods" of most polytheistic and monotheistic pantheons are actually powerful, immortal human-like races from other dimensions who visited Earth in ancient times, and became the basis of many legends that would come to form the basis of the world's religions. Most of these "gods" then left Earth for centuries, only adding to their mystery.

Now, obviously, not all such legends can be true, since they contradict scientific facts, as well as each other. As for which parts of which legends are true, and which are just lore, that hasn't been entirely established. Additionally, most writers in the past have not been the most thorough in fact checking how these various mythos intersect with one another, and as such, complications and contradictions can arise.

To greatly oversimplify things, the cosmic being the One-Above-All has, up to this point, been hinted at as the supreme being in the Marvel Multiverse. In addition, Marvel uses a "Big Bang" theory to explain the creation of the universe itself; the creation of the specific planet Earth is passively considered a part of this big bang. The creation aspects of the various gods are considered part of the legends that became the basis of the religions.

Some of the various "God(s)" of the Marvel Universe, and parts of their mythos, have been blended into the Marvel Universe in various ways; for instance, the Nine Realms of the Asgardian mythos have been visted by numerous characters, showing that they do in fact exist; however, Yggdrasill, the "world tree" that connects the Nine Realms in Asgardian lore, seems to contradict basic scientific fact.

If you'd like I can go more in depth with the aspect of Religion in the Marvel Universe, or with the more cosmic aspects of the Marvel Universe, like the creation of the universe, but for now, I hope the above kind of helped explain the workings of Marvel religion