Prayer is for many, if not all, just an attempt to feel good about doing nothing. It is looking for the feeling of doing something when in fact nothing is done. Even the believer has to admit that prayer is really doing nothing for another person.
Suppose God is the big witch in the sky and can do magic. Praying never escapes the suspicion of being a polite form of magic. Then why should we do the magic as if he does not have the wit or power do it himself? We may do it to feel in control. Or we may be trying to in fact twist his arm for we have zero trust for him.
Prayer is trust but real trust means you expect specific results. The results sought by prayer are so vague and open to interpretation and too far into the future that it is not trust.
Trusting a criminal boss to pay your wage means you have some idea of what the wage will be and when and how you will get it. It does not mean you trust he will pay it or enough of it by the time you are 90. What you are trying to do is just feel and lull yourself into a false sense of security. You are not really trying to trust or to be mature.
You could be praying in order to work up a feeling of trust in something bigger than yourself. But even if there is a God who can be trusted, praying to feel trust means you want to feel trust and don't care if you should. It is not about realising that God really can be trusted. You never know if a person of faith really is a person of faith. And the more they exhibit their faith and insist they believe the more reason there is to doubt them.
Prayer is not about trying to change anything but to unite to God and opening yourself up to being like him. This is what many religions say.
God knows what is best. We might pray for healing. And it may come. Did God answer the prayer then? That depends on his motive. Did he do it to answer the prayer or did he do it just because it was the right thing to do? If he did it because he was asked, then it was not because it was right. Maybe he did it both because he was asked and because it was right? That means he refused to do it entirely because it was right. In so far as God does not do it because it is right he is acting amorally if not immorally. As he claims to be good, he would be showing he is not perfectly good. Then prayer is saying, "I don't care if you are evil or not do what I ask!" How is that supposed to help us become more virtuous? No wonder there is nothing remarkable about the virtue of most believers. Any virtue they have is there in spite of their faith and their prayers.
The believer feels he has done something for another person when he prays. That is really putting faith before people. You should only feel you have done something when you have really done something. What would you think of a witch who did nothing for the poor but cast spells for them?
Some people say prayer is good because it is not about asking for favours or getting them but about developing and sustaining a relationship with God who you trust to do the right thing even if it makes you suffer. They compare it to a pet cat who suffers at the vets and does not understand what is going on but trusts her owner and the vet that they do not have it in for her.
Psychologists who regard prayer as an exercise in superstition, cognitive dissonance and wishful thinking may still think it has its good side as it is about expressing a relationship with the divine or sacred. Some say this good side is enough to justify encouraging prayer and others say it is not enough.
But trust is not good for its own sake. It is good because without it we would let nobody help us. The cat is not trusting God so it is not the same thing. It is cruel to encourage people to put overwhelming trust in a being who may not exist or in a being whose existence cannot be proven in the way you can prove you must have parents.
Jeremiah 7:16 has God telling the prophet not to pray for the people. It is as if God is saying that prayer will be answered and God has to comply. So to hurt somebody just don't pray for them!
This more occultism than religion.Many atheists feel a unity with the human race and bestow the trust some give to God on it. And they do the sane and right thing.