Prayer presents a philosophical difficulty. It seems to have the power to change what God already decreed for a person’s life. But does that not involve the seemingly impossible function of changing God’s will? Prayer does not change God’s will but transforms the person. Through prayer a person becomes primed and fitting to receive the divine flow. Prayer transforms him from bad to good, making him deserving of divine goodness.

Does prayer change God’s will?

What has brought people to doubt [the efficacy of] prayer…is that they say that the following possibilities are unavoidable: If some good was decreed by God for someone, there is no need for prayer. And if that good was not decreed, how can prayer be effective to change God’s will, so He will [now] decree good that he hadn’t decreed earlier? For God does not change from willing something to not willing it or from not willing it to willing it.

Prayer transforms a person:

This approach is incorrect. For influences from above will influence the one receiving them only when he is at a specific level and properly prepared to receive them. If a person does not prepare himself for receiving that flow of influence from above, he prevents the good from reaching him. If, for instance, it was decreed that a man’s grain harvest should be successful in a certain year, but he did not plow or sow that year – then even if God sends powerful rains upon the earth, that man’s harvest will not be successful, since he neither plowed nor sowed. He prevented the goodness from reaching him, because he did not prepare himself to receive it…. In a similar vein, the effectiveness of prayer or of proper action can be explained. The one who prays prepares himself to receive the flow of goodness or cancels the misfortune that was decreed upon him, by changing his own spiritual level. (Rav Yosef Albo, Sefer HaIkkarim 4:18)