What is Faith?

Andrew at the City of God states very clearly what faith is. I couldn't have said it better myself:

Something amazing, and yet incredibly simple, occurred to me today.

Faith is trusting in the good God whom we know even when we don’t know how He is consistent with the things we see.

Since we know this good God, we know everything must be consistent with Him in some way, but we can’t always explain how. Faith is simply not suppressing that knowledge in those situations.

This means that, from a philosophical/apologetical perspective, there is absolutely no evidence against the existence of the Christian God, since God has a) revealed Himself to us, and b) made clear there will be times when we have to fight off the temptation to claim we don’t know Him because of our ignorance about how some things are consistent with him. Thus, in an ironic way, situations that seem inconsistent with God and His goodness serve to prove His goodness nonetheless.

Or to put this all another way: there is no neutrality when it comes to God, and God really does exist.

Now faith is the assurance of things hoped for, the conviction of things not seen.

For we walk by faith, not by sight.

And he said, “Abba, Father, all things are possible for you. Remove this cup from me. Yet not what I will, but what you will.” … Behold, the hour is coming, indeed it has come, when you will be scattered, each to his own home, and will leave me alone. Yet I am not alone, for the Father is with me. I have said these things to you, that in me you may have peace. In the world you will have tribulation. But take heart; I have overcome the world.