(It's against his programming to impersonate one.)
Here's one aspect of D&D that I've never had much occasion to bother with. Since most of the campaigns I've ever run have been set in a pseudo-European Middle Ages, Renaissance, Enlightenment, or Industrial Revolution, the settings themselves have also tended towards pseudo-European religion. It's usually a vague sort of monotheism without any reference to theological particulars. This suits me just fine, as an imitator of JRPGs (which are also sometimes prone to doing this, or even never mentioning God at all but going on and on about the monolithic Church). It also meshes really well with the very simple treatment of religion in Classic D&D: there's Law for good guys and Chaos for bad guys, and that's it. Deities, demigods, and immortals optional.
I suppose it has to do with the rather unusual assumption of ancient polytheism in a setting that otherwise always looks like Medieval or Early Modern Europe. It just doesn't jive, does it? If I were ever to set a game in Ancient times, something more like mythical Greece or Rome or Persia or Egypt, or going further back, the Hyborian Age or Atlantis, well, okay then. You've got to have a pantheon for that. But so far, I haven't done this. As much as I love ancient history and mythology, a campaign set in such a world has yet to strike me as compelling.
For my upcoming space opera campaign, I'm going to do something else altogether, something seen in JRPGs, in Star Wars, and a few other places: there will be two metaphysical forces at work in the universe, the Light and the Darkness. The player characters, presumably being heroes, fight for the Light and against the Darkness. There will even be an order of psionic monks and knights who specifically espouse the philosophy of Light (because a good fantasy campaign needs its clerics, and in a good space opera campaign, that means Jedi). On the other hand, two out of the three Big Bad Evil Empires in the setting will be fairly strict in their state-sanctioned theisms, leading to plenty of tension between these various institutions. Always a good backdrop for a moving and shaking, strife-ridden campaign setting.
It occurs to me that at some point soon, I'll have to devote one of these posts to actually explaining the setting for my next game. Friday, then... "G" will be for "galaxy"!