cognitive faculties

why is it that some people can have 5 million unanswered questions about their own faith and still believe?
why is it that those same unanswered questions prohibit others from believing?

why is it that some things seem unexplainable/unfathomable
and that those things are still accepted as truth by some
and that those things are deemed untruth or lies by others.

why is it that God have given us minds longing to understand, yet gives us faith rather than understanding?