[For the full sermon, see Man's difficulty concerning prayer.]
"How should any design of the All-wise be altered in response to prayer of ours? How are we to believe such a thing?" By reflecting that he is the All-wise, who sees before Him, and will not block His path.... Does God care for suns and planets and satellites, for divine mathematics and ordered harmonies, more than for His children? I venture to say He cares more for oxen than for those. He lays no plans irrespective of His children; and, His design being that they shall be free, active, live things, He sees that space shall be kept for them....
What stupidity of perfection would that be which left no margin about God's work, no room for change of plan upon change of fact--yea, even the mighty change that... now at length His child is praying! ... I may move my arm as I please: shall God be unable so to move His? ...
If His machine interfered with His answering the prayer of a single child, He would sweep it from Him--not to bring back chaos but to make room for His child.... We must remember that God is not occupied with a grand toy of worlds and suns and planets, of attractions and repulsions, of agglomerations and crystallizations, of forces and waves; that these but constitute a portion of His workshops and tools for the bringing out of righteous men and women to fill His house of love withal....
In all His miracles Jesus did only in miniature what His Father does ever in the great. Poor, indeed, was the making of the wine in the... pots of stone, compared with its making in the lovely growth of the vine with its clusters of swelling grapes--the live roots gathering from the earth the water that had to be borne in pitchers and poured into the great vases; but it is precious as the interpreter of the same, even in its being the outcome of Our Lord's sympathy with ordinary human rejoicing.... At the prayer of His mother, He made room in His plans for the thing she desired. It was not His wish then to work a miracle, but if His mother wished it, He would. He did for His mother what for His own part He would rather have left alone. Not always did He do as His mother would have Him; but this was a case in which He could do so, for it would interfere nowise with the will of His Father.... The Son, then, could change His intent and spoil nothing: so, I say, can the Father; for the Son does nothing but what He sees the Father do....
And why should the good of anyone depend on the prayer of another? I can only answer with the return question, "Why should my love be powerless to help another?" ...
From George MacDonald: 365 Readings by C. S. Lewis.