The Bible is physical evidence, its a combination of 66 different books written by 40 different authors all put together to make 1 big book of the accounts and life of Christ. The "faith" part doesn't refer to whether he existed or not, it refers to a requirement needed to make it in to heaven. Sadly...there's a ton of evidence of his existence but a lot of influential people of today deem it "questionable"... funny thing is, even that was foretold in the bible.
The original books of the bible only make reference to the coming of a christ.
The story of christ and all thing christian come from the new testament.
There were many stories accounting for the existence of El and Elohim(aliens), that created man, there are books of the bible called the apocrypha
http://en.wikipedia.org/wiki/Biblical_apocrypha.
The stories didnt make the final cut of the bible(a book made by men from a collection of ancient myths and legends) because they had contradictions or spoke of gods in plural sense.
Religious scholars have found that many of the stories relating to jesus had previously been applied to other deities long before Jesus ever existed, they performed the same miracles had the same disciples, check out the story of Mithra(ancient religion going back to babylon and Sumeria), or Apollo, both born under a bright star, to a virgin mother, 3 kings/wise men, there are also at least 20 others, they share many similarities with Jesus like walking on water, and healing the sick.
By Gods own words(according to the story of moses and the 10 commandments) "Thou Shalt not worship idols", what is jesus if not an idol?
If books are what it takes to prove the existence of something then there are extensive books on the subject of UFO's and alien contact with mankind since the beginning of civilisation. Myths surrounding the Elohim and Atlantis.
Even the bible itself talks of the Nephilim, the offspring of gods and man, which were giants and titans. "Men of renown" Nimrod who built the tower of babel is said to be one of these. I cant really go too much into it because religious discussion is banned on this forum and I have said too much already, so I will leave it at that.
But faith by definition is a belief in something that cannot be proven. Hence it taking faith. There is vast evidence to support the existence of aliens, and the bible supports it.
I believe in God, Im not an athiest, I ask no prophet to be my saviour or to save my soul, my worship is directed solely at the one creator of the universe and all things.
I believe in no "organised" religion, designed to control the masses, or forced on the world at the end of a sword. I dont believe in something used for political reasons since the fall of the roman empires military might.
Organised religions are religion that has been taken by men and used for their own gain, corrupting the very core of it. My God speaks to me from within, intuition used to decide whats right from whats wrong,(not true vs false, but good vs evil).
On that note Ill leave it there, but there is plenty food for thought when it comes to that subject.
Sorry fade for bringing religion into this but the point i was making was the basis of a belief in something without physical evidence.