Closest thing to the Christianity in TES were the Alessian Order. Making many previous dieties saints and worshipping one true god. Direnni stoped this when they killed off the order.
Skaal are animistic, but they still do have one superior diety. I like the term DarthOrc introduced, pantheism.
Nords, however, were not like Skaal at all, they had and have their separate pantheoin, that I don't think has changed too much. (With the Empire, Nordic pantheoin lost a bit of it's popularity, but didn't disappear).
Overall, the TES universe is mostly hinduism inspired. May not seem like it in Skyrim. But it's pretty easy to notice once you read more of the lorebooks and if you've played through Morrowind.