C.S. Lewis on Prayer

So I'm reading this book called "Prayer" by Philip Yancy that I highly recommend. Only in part because Yancy has a sweet, grey 'fro. Anyway...he quotes C.S. Lewis & Lewis always says it best:

"The essence of a request, as distinct from compulsion, is that it may or may not be granted. And if an infinitely wise Being listens to the requests of finite and foolish creatures, of course He will sometimes grant and sometimes refuse them. Invariable 'success' in prayer would not prove the Christian doctrine at all. It would prove something much more like magic.

It is not unreasonable for a headmaster to say, "Such and such things you may do according to the fixed rule of this school. But such and such other things are too dangerous to be left to general rules. If you want to do them you much come and make a request and talk over the whole matter with me in my study. And then - we'll see."