The fact that religion is a big deal on the show bolsters the sense that it’s dismantling the illusion of free will. People and Cylons both sense they are at the mercy of omniscient deities, and the fact that they have oracles and visions only confirms this. Destiny is unavoidable on the show; what’s happening now has happened before doesn’t have to be taken literally, it could just mean that the path ahead has no branches, no alternate possibilities, that the future was written literally (by the gods) or metaphorically (by the convergence of forces that necessitate certain outcomes). Omniscient gods pretty much preclude the possibility of free will, and while there’s plenty of strained attempts to argue otherwise, they’re just the result of hope trumping logic. Religion is a projection of ego—I feel my life is meaningful, so there must be an outside force validating that—and the stubborn insistence on free will is a projection of ego. The two are wed together out of human egotism, but they don’t really make sense together logically.