“Love the Lord with all your heart, and with all your soul,
and with all your MIND”--Matt 22:37
Question: Why pray if God is omnipotent and omniscient?
In other words, what's the point of prayer of petition, especially if God's will is going to be done anyway?
I've heard it said that the reason we pray is not because it changes God, but that it changes us. I think this is a good and appropriate answer, but I also think it is incomplete.
This is from Peter Kreeft's book, "The God Who Loves Us" and I think wiser words were never written to answer this question. He states:"Why pray? Because we are commanded to. Pascal answers, “God instituted prayer to communicate to his creatures the dignity of causality.” If you say that we should not pray because God already knows our needs, then you must say that we should not farm or eat or read for the same reason. God lets us really cause events and really lets us make a difference not only by physical work but also by spiritual work."
That is, in giving us the "dignity of causality" God has allowed us the supreme privilege of being able to actually cause a change in events. We are given the dignity of working (spiritually as it were, through prayer) to effect (or cause) a result, just as it is indeed a privilege to be able to do physical work (Monday mornings notwithstanding . (Think of the spoiled and obnoxious adult who has had every single thing handed to him, never having to lift a finger. This type of "inability to work" corrodes our humanity. Thus, it is indeed a supreme privilege to be able to work/labor. And God has given us the dignity of being allowed to do spiritual work (i.e pray) for an effect.)
Thus, God does not miraculously produce wheat in our fields. We must farm them in order to get our food. And God does not miraculously produce cures in our ill. We must pray these healings into existence and by our prayers contribute to causing a change. "If it is foolish and impudent to ask for victory in a war (on the ground that God might be expected to know best), it would be equally foolish and impudent to put on a mackintosh - does not God know best whether you ought to be wet or dry? The two methods by which we are allowed to produce events may be called work and prayer. Both are alike in this respect – that in both we try to produce a state of affairs which God has not (or at any rate not yet) seen fit to provide 'on HIS own'. And from this point of view the old maxim laborare est orare (work is prayer) takes on a new meaning. “What we do when we weed a field is not quite different from what we do when we pray for a good harvest."source.
An interesting corollary to this discussion arises about what God's will is and if we can "change" it through our prayer. God, in one sense, does not and cannot "change". And all that occurs is part of His Will. However, there's a difference between God's antecedent will, and God's consequent will. The antecedent will is, essentially and inevitably, fulfilled. The consequent will, however, is that which has its origins in our choices.