Marvel has a tense theology. Let’s lay some quick groundwork before tackling it.
One of the fundamental principles of classical monotheism is the Creator-creature distinction. Imagine a bubble. Inside is all of time and space from beginning to end. At one end of the bubble is the first domino ever knocked over, and all of reality ripples out from that first action, that first moment of creation.
Now, standing outside the bubble, outside of time and space and the chain of causality and reality as we can understand it, is the Creator. The Creator caused everything else to exist, and caused it to exist in the way it exists. But the Creator himself stands outside of that bubble of spacetime. Nothing made him exist. He just exists because that is what he does. He is the uncaused cause, the unmoved mover. Among other things.
In a monotheistic universe, all of reality is shaped by the personality and by the will of the Creator. To a very great extent, everything is just mimicking what Dad does. Each thing’s meaning is defined by the meaning he gave it, and its purpose by the intensions he has for it. And because he authored it all, he has authority over it.
In the Marvel universe, and in the imagination of those who deny any such being standing outside and independent of spacetime, this is not so. Puny mortals, superheroes, and gods all exist on a spectrum. There is no fundamental distinction between them.
Take Spiderman. Spiderman has superhuman sense, superhuman reflexes, and cool web-shooters. Your average Joe might be tempted to think his powers were supernatural, even godlike. But set him next to Thor, and there’s no comparison. Thor’s got mojo. He is so clearly godlike in comparison to Peter Parker, earthlings actually worship him. But set him next to Jean Grey (a.k.a. Phoenix), and again, there’s no comparison. So what if Thor is really strong and can fly? So what if he apparently lives for eons? Phoenix is more powerful than death itself. She controls space, she controls time, and she controls the thoughts inside a person’s mind, given a good excuse. Can most of the gods of classical paganism claim that?
And that’s why Joss Whedon’s refusal to let the Avengers bow before Loki makes sense. Sure, he’s a “god,” relatively speaking. He’s got oomph. He has power. But fundamentally he’s no different than any other creature zooming around the Marvel universe. Under the right set of circumstances, he can have all that taken away. Under the right set of circumstances—say, acquiring the Infinity Gauntlet—a puny human as klutzy and awkward and harebrained as Peter Quill might become top dog in the universe. The difference between one Marvel character and another is just degrees of power, which can be won or lost. There’s no real difference in kind.
And that’s why Captain America’s offhand remark that there’s only one God is such a big freaking deal. Perhaps Joss and the producers meant it as an offhand funny remark from a charmingly out-of-date super-patriot, but it has major implications. If Captain America believes that there is still a real God, a transcendent God, someone who stands outside of the bubble and stands as Lord of the whole shebang and judge of the actions of the Avengers and those around them—that changes everything.
In a world where the chain of being is all there is, there’s no reason for Iron Man or Thor or anybody else not to play with morality. There’s no reason they shouldn’t cross a line to get things done, let a few people die in order to save the world. Break a few eggs to make an omelet. The ends justify the means. It all comes down to what you think the greater good is and what you think you can get away with. Besides, if the other guy is bigger than you, and you let something as petty as your qualms about personal freedoms, or the sanctity of life, or whatever else get in your way, you’re going to regret it. There’s no room for that in the big leagues.
But if there is a just God standing outside of that chain of being, then you might be held accountable to him. The ends do not necessarily justify the means. Superheroes do not get a blank check and a free pass when they run around destroying cities or overthrowing democratically elected governments. There is a judge who will see justice done in the long run, and you are not him. And you might guess where I’m going with this.
Marvel’s Civil War plotline is ultimately about this question. In the grand scheme of things, are there limits to the authority of the guys with the supersuits and magic powers? Are they to be held to the standards of common mortals? Is there a God standing outside the universe who presides over the destinies of planets and the fates of the Avengers, or is it all a conflict between different degrees of power in a mechanistic cosmos? If the former, let’s put some brakes on Tony Stark. If the latter… maybe we leave the tough calls up to him. After all, he’s bigger.
Before I bring this in for a landing, let’s bring in another fictional universe. This is why H.P. Lovecraft, the materialist par excellence, is so comfortable with a universe filled with so many gods. The line between atheism and polytheism isn’t one that separates two fundamentally different mythologies. It’s just a question of terminology. If you believe that the world is one vast uncaring void, then maybe some small creatures the universe doesn’t care about worship other, larger creatures the universe also doesn’t care about. The gods of a polytheistic universe aren’t deities in any ultimate or transcendent sense, but they sure do look like it compared to the ants walking around beneath them. The Christian—or Muslim, or Jewish—disbelief in the gods of polytheism is simply nothing like the atheist’s or some polytheists’ disbelief in the Creator God.
And that is why Captain America can still not believe in pagan gods, even after hanging out with one.