Why are there no Empirical Facts for a God to exist?

Why are the events only in the bible and not taken into account of firsthand observers, philosophers, or scholars at this time? Surely these amazing stories would have been documented by the onlookers, and no evidence. But the evidence has shown such facts about other rulers such as Ramses II, which are documented, a mummy & tomb etc...? Christians don't you think its a little strange that the stories are only contained within the bible? Would it be reasonable to say we know what Hilter (Catholic) did with all his killings and NOT ONE written account for future generations except which was written by Hitlers closest follower in one book, with no other accounts?