Prayer is supposedly asking God to help while magic is trying to make help happen.  Magic is an sort of ethical way of helping people. Prayer isn't. Magic is attempting to do something for them – it is supposedly sending power out to enfold them in love and hold them and protect them. Sadly magic is futile and self-deluding but prayer is worse.

Magical ceremonies are phrased like prayers but are actually spells.  So you could be casting a spell and calling it prayer.
With magic, you can experiment in the hope of seeing results. With prayer, nothing whatever proves success or failure. There is always an excuse when the prayers are not answered. Usually it is that the answer was received but just not recognised. Prayer affirms that you don't have the right to do tests or seek proof. Anything that is supposed to be so important and is neither verifiable or falsifiable is really just an affirmation that says: "I have no right to learn the things that are most important. I am therefore worthless." Prayer makes artificial demons that need to be exorcised.
Using prayer to do your will is different and is actually magic not prayer. Proper prayer calls for help and then blocks that help. It is really about kidding yourself that you are doing something for others.
To pray for a person is really doing nothing for them. You may see it as an attempt at magic. But it is really asking for your magic to fail because prayer implies that you are not the one that has the magic and somebody else, God perhaps, does. It injures the person prayed for in the sense that you are keeping the magic from them that they need.

If magic works and prayer is magic then prayer blocks magic from showing results.  Prayer is sending out a spell, "Make sure that spells for a wage rise or healing or money or whatever don't work."  The spell I decree is this ,"Let the energy seem to respond to asking as if it is a higher powers choice whether to help or not."  It is magic against magic.