The above already included more than Lewis did; (Lewis’ selection ended with ‘…how can he pray?’)
But despite my expansion on Lewis above, I cannot resist including the entire next paragraphs also from the same sermon, being so germane as they are to so much that interests this forum). Here it is.
As to the so-called scientific challenge to prove the efficacy of prayer by the result of simultaneous petition, I am almost ashamed to allude to it. There should be light enough in science itself to show the proposal absurd. A God capable of being so moved in one direction or another, is a God not worth believing in–could not be the God believed in by Jesus Christ–and he said he knew. A God that should fail to hear, receive, attend to one single prayer, the feeblest or worst, I cannot believe in; but a God that would grant every request of every man or every company of men, would be an evil God–that is no God, but a demon. That God should hang in the thought-atmosphere like a windmill, waiting till men enough should combine and send out prayer in sufficient force to turn his outspread arms, is an idea too absurd. God waits to be gracious not to be tempted. A man capable of proposing such a test, could have in his mind no worthy representative idea of a God, and might well disbelieve in any: it is better to disbelieve than believe in a God unworthy.
‘But I want to believe in God. I want to know that there is a God that answers prayer, that I may believe in him. There was a time when I believed in him. I prayed to him in great and sore trouble of heart and mind, and he did not hear me. I have not prayed since.’
How do you know that he did not hear you?
‘He did not give me what I asked, though the weal of my soul hung on it.’
In your judgment. Perhaps he knew better.
‘I am the worse for his refusal. I would have believed in him if he had heard me.’
Till the next desire came which he would not grant, and then you would have turned your God away. A desirable believer you would have made! A worthy brother to him who thought nothing fit to give the Father less than his all! You would accept of him no decision against your desire! That ungranted, there was no God, or not a good one! I think I will not argue with you more. This only I will say: God has not to consider his children only at the moment of their prayer. Should he be willing to give a man the thing he knows he would afterwards wish he had not given him? If a man be not fit to be refused, if he be not ready to be treated with love’s severity, what he wishes may perhaps be given him in order that he may wish it had not been given him; but barely to give a man what he wants because he wants it, and without farther purpose of his good, would be to let a poor ignorant child take his fate into his own hands–the cruelty of a devil. Yet is every prayer heard; and the real soul of the prayer may require, for its real answer, that it should not be granted in the form in which it is requested.