Belief in God isn't for me, some fact we're taught or given. It isn't a lesson like "if you drop an apple, it'll fall to the ground."
It's an experience that gives context to the facts.
If, at one time, our best observation and understanding said, "the sun travels around the earth," finding out otherwise doesn't mean that our ancestors in faith who believed were unfaithful or heretics for writing poetry thanking God for the sun's daily travel. It means we now write songs of praise for the yearly trip that the earth takes around the sun.
And if we once thought mythologically and made up stories to explain a creation that gave credit to God for our being, the fact that we now investigate scientifically and think that we have generations of development---yes, evolution---behind our being makes us no less indebted to God.
Why is this such a threatening idea?