(quote) Dave-104327 said: There's another option you forget which is, "here's something even worse." God is not likely to rearrange the timeline of anyone's life based on a prayer chain, or a novena or a rosary. (I say not likely since I do not pretend to know the mind of God, and I still believe that He can do anything if He so chooses) But many religious people do think they can know God's mind and use prayer as a way to alter events. Predestination is frowned upon by the RCC but it's kind of the way things really work. However, I would like to have another word to define it. We've all heard the slot machine analogy to prayer. St. Monica was just feeding the prayer slot. I greatly admire her tenaciousness, but it was in a way self-serving. She might well have been capable of great things that she did not attempt. She chose rather to spend all that time praying for Augustine who was going to convert in the long run anyway.
Miracles of healing, which are very thoroughly investigated by the Church, are required before saints are canonized, so there is ample evidence that such occurrences do indeed occur.
The reason religious people pray is not because they think they can understand God's mind, but because they have faith that God is pleased by prayer and will act on them in a manner that is in accord with His will (i.e., invoke His active will in place of His permissive will). The is a fundamental principle of out faith, which is revealed in Scripture (both the Old and New Testaments) as well as being part of Sacred Tradition.
Yes, it is possible God may answer our prayers in a way that we don't care for. Subjectively, the response may seem worse than what we request; however, objectively it is directed to improving our eternal salvation -- the only outcome that really matters.