Some people believe that there is only one true god. Some believe there are multiple gods. Others are convinced that there is no god at all. And no amount of debate nor evidence will convince anyone to change their mind. Why do people come to different conclusions, despite having all the same facts?
Everything is possible. Nothing can be ruled out for certain. All universes exist. Much like Schrödinger's cat, god is simultaneously a fact in one universe, and a myth in another.
So the question becomes, how should we act, given we don't know which of the possible universes we are actually in? This is not so much a question of likelihoods, but rather a question of utility, that is, how much do we personally value each of the possible outcomes.
An analogy:
Your only son gets accused of murder.
The evidence against him is strong.
The jury unanimously declares him guilty, and sentences him to life imprisonment.
He insists that he's innocent, and begs you to believe him.
But why should you? You heard the exact same evidence that the jury did.
Nevertheless, you visit him every day you get the chance. You still have faith that he's innocent, despite the evidence against him.
And what good parent wouldn't? Imagine if he was actually innocent and you, his own parent, rejected him.
Without him, your life is meaningless anyway. So you cling to that 1 in 1000 chance that he might be innocent, in the
hope that one-day he'll be freed.
So too with god. Some people cannot accept themselves as the product of random chance. I
can. But they can't. So they choose to act as if there's a god, because that's the only universe that matters to them. And I choose to act as if there is no god, because the universe in which I control my own life is the only universe that matters to me.
And that's faith. It has nothing to do with what you know,
it has everything to do with how you choose to place your bet based on
the utility you assign to each
outcome.