I think everybody knows there has to be a higher power. That's not Biblical faith. That's not Christian faith. This universal intuition, this thing that everybody knows about God, is not faith. Nor is faith a kind of general optimism.
Some people are quite sure that everything is going to turn out all right.
They don't know how. They don't know who's going to make it turn out all right, but they're pretty sure that somehow life will work out. It may stem from the fact that they have excellent health or good digestion. Poor health will make you pessimistic and good health tends to make people optimistic. This optimism may stem from a lot of good experiences they have had in life.