There are several checks on religious doctrines that can and should be done.
There are probably a lot more checks that are done and should be done. But notice we aren't turning a blind eye to observations. Sometimes we discount them on faith that the bible is right and the observation must be wrong. And in many cases we have eventually been proven right to have discounted them. Some we have yet to be proven right on.
Religous doctrines usually derive from some religous authority. That authority should be examined.
For example, the first five books of the Bible get their authority directly from Moses. Moses' authority comes from the fact that he was confirmed by a number of miracles before Israel and Egypt to be God's prophet. A case for proper authority can be made for practically all scripture in the Judeo Christian religion.