The following quote is taken from the material for the Bible study lesson I'm teaching tomorrow night on the topic of prayer. While there are a few places I'd quibble over the way Lewis says things, I fully agree with the point he is making:
The two methods by which we are allowed to produce events may be called work and prayer...The kind of causality we exercise by work is, so to speak, divinely guaranteed, and therefore ruthless. By it we are free to do ourselves as much harm as we please. But the kind which we exercise by prayer is not like that; God has left Himself a discretionary power. Had He not done so, prayer would be an activity too dangerous for man...C. S. Lewis, God in the Dock, from newspaper article "Work and Prayer" published in 1945.
Prayers are not always - in the crude, factual sense of the word - "granted". This is not because prayer is a weaker kind of causality, but because it is a stronger kind. When it "works" at all it works unlimited by space and time. That is why God has retained a discretionary power of granting or refusing it; except on that condition, prayer would destroy us. It is not unreasonable for a headmaster to say, "Such and such things you may do according to the fixed rules 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 must come and make a request and talk over the whole matter with me in my study. And the - we'll see."
Prayer is phenomenally powerful. When we pray, we are asking the God who created the universe that we know, the God who exists beyond our concepts of space and time, to reach down and act.
It is perfectly reasonable that God chooses how to answer - yes, no or wait - as He alone can see all the ramifications of what we ask. Sometimes, the answer is yes, but in a way so unexpected that all we can do is stand back and wonder. On occasion, a subsequent event will make clear why a "no" answer was needed to a particular supplication. Waiting is perhaps the most difficult answer to receive, yet the blessings received when the waiting is over are usually far beyond what we could ever have anticipated.
And yes: there are times when a "no" answer to a petition makes it seem as if God has abandoned us, left us to suffer for no reason. "Why not?" we cry, but the answer comes softly, "Trust Me." At the very moment our faith may be failing, we are asked to continue to trust, continue to believe that even this will work out for His glory.
*I'm cleaning out the "drafts" folder - this was dated 4/2/08. I have no clear recollection of what prompted the post, but liked the point it made too much to simply delete it.