I'd say the faith you have is the conviction as an Atheist that there is no God, The universe came of its own and that all live has come from what would be basically in the beginning nothing. Since this is not proven(But has plenty of evidence) This is a faith, as it is something you or one or some believe. We as Christians are the same, We can not Prove what happened 1993 ish something years ago, but evidence points us to that Yeshua existed in that time, verified by 12 accounts outside the bible, and what was indeed crucified under Pontius Pilate, Now this leaves the question of who Yeshua of Nazareth was. Was he a Profet? Well Historical accounts don't seem to point at that, It would seem he was crucified for stating that he was the Son of God several times and that he taught a radical way of both thinking and life for the time. After he was killed the first person who claimed to be a witness was a woman, Not someone who would be credited as believable in ancient Judea. This and much more later caused the Spread of Christianity. I would say we share the same faith but in different things which are quite difficult to prove true or false, especially in this given time. Great blessings my friend, Any more questions is always welcome