The Bible is just one of several sources for examination. Back in the 1940's, a British theologian named Braithwaite, came out with a really intriguing idea. He said that theology has a purpose. It is a group of ideas about God that is supposed to get the believer to act a certain way. All the rest is merely intellectual fluff.
Lets look at that.
Take the doctrine of the Trinity. The alternative is monotheism, God as a Monad, who is removed from Life - a single, unified entity, at the top of a vertical chain of command and responsible to no one. Monotheism is the stack pole of Judaism. God shares rulership with no one else and the unseen reality is not fractured into numerous, competitive and mischievous gods. People who believe in God this way act despotically.