We are most reasonable when we use the most reasonable definitions of words.
Faith: Trusting in truth
Evidence: Available body of facts(including the fact that claims have been made)
Claims are evidence of truth(either the truth that the claim is wrong or right). Now most claims can be shown to be wrong either through questioning or other evidence that disproves the claim.
The claim "unicorns are real" can never be shown to be wrong, but the fact that no one is honestly claiming this is reason to believe unicorns are not real.
The claim "God is real" can never be shown to be wrong, but the fact that many people make this claim, is reason to believe God is possibly real. The question is which God? Again, it comes down to how reasonable the claims are. If Christians make the most reasonable arguments for the existence of God, then it's reasonable to assume the Christian God is real because of the fact(evidence) that Christian's make the most reasonable arguments for the existence of God. If their arguments make you think in new and different ways, then that's a good thing, if their arguments make you think their dumb, then that's obviously not a good thing.
At the end of the day, the person who has better reasons and logic behind what they believe, is the most reasonable person to believe. However, you're still free to not believe them and resort back to skepticism because of the implications of their beliefs.