What Don't I Know About Faith

I've called faith a power to act informed by vision. That vision is informed by interpretation of experience, but a little optimism seems to help.
I've used the following little story as an example of the working of faith. One goes into his house at night with the thought that the electrical system has gone to hell and there is no way the light switch is going to work. He may spent the night in the dark. With a bit of faith he may be motivated to try the switch. Trying the switch he may still spend the night in the dark, but he has improved his chances for light. With continued faith he may repair a malfunctioning switch or an electrical system that has gone to hell.

What more were it good I learned of faith?