It doesn't make any difference that people around the world believe all kinds of things that we can be reasonably certain don't happen, then? That's okay as long as they really trust the authorities who tell them these things are right?
So, when a bunch of people trust a leader who tells them to sell everything they have and meet on a hilltop to be picked up by an alien spacecraft, that's okay for them to do that. That's just how faith is.
Extend that...Someone tells us a virgin was told by an invisible spirit that she was pregnant and would have a child fathered by an invisible spirit, we should believe that this actually happened because we trust the person who told us this, and that person assures us that it's true. So, while we don't know how this person whom we trust knows it's true, but we agree to believe it is. We ask, "How do you know that's true?" The answer is, "It says so in the Bible, and I know the Bible is true because it tells me it's the Word of God."
What's the difference?