...a great deal of it is tradition? And not text?
Examples:
-The modern image of angels, people with bird like wings, was created by Raphael. The Bible never went into any great detail about them, and for all you know they could of meant to be bat like wings.
-The devil in it's self is VERY liberally put together. Every evil spirit is instantly assumed to be the devil. It's like he was put together to be a contemporary of God.
-The tons of Paganism in the religion from a cultural adaptation. Christmas is a mess of Pagan traditions.