Prayer is the way most religions expect people to communicate with their supreme being. If a supreme being doesn’t exist then you are essentially just talking to yourself. Prayer could be considered harmless if it was just a conversation with a nonexistent deity. However, prayer is often an expression of our hopes and desires that we are trying to share with a supreme being. This is done in the hope that the supreme being will help us or someone else.
Hope in itself is not a bad thing; but to put our hopes and dreams with a supreme being that may or may not answer us is foolish if we do nothing else but pray. If you are still holding on to the idea of the power of prayer then do yourself a favor and pray for the proof that it works. I have honestly prayed for such a thing when I was a believer and I still have not seen or felt the proof.
Why does all of the praying in the world not stop war or any other atrocities? Why are the innocent harmed and left to die with their loved ones praying over them as they pass away? If every believer were to pray that the sun turn blue for a day as proof of the power of prayer, do you really think it would happen?
The Christian Bible says that if you have faith you can pray for a mountain to throw itself into the sea and it will happen. I have seen a lot of praying in my life and the effects of it are no different than the normal hope for something to happen. Both have no direct impact on reality. Fortunately, few people actually rely on prayer or hope alone to solve their problems.
The main problem I have with prayer is that you are transferring your hope to someone else. If I were to pray that a serial killer is captured, then I assume divine intervention will step in and do this. There is nothing I can do that will match God’s ability, so why should I do anything? However, if I have a personal hope for the same thing, I might remain mindful of the fact that I could actually help find a serial killer. I could be observant of my surroundings for anything suspicious or for the people or vehicles the authorities are looking for and actually help accomplish something.
Hope is a good thing. Hope is the general feeling that a desire will be fulfilled. I hope for peace on Earth. This hope for peace, just like a prayer, does nothing on its own other than to keep that goal in my mind as something that is achievable. I may act on that desire to somehow promote peace when a time comes that I may be able to influence the whole Earth or at least some part of it.
If a person were wounded and appeared to be dying I would obviously hope that they would be healed. If I were to pray for the person's life to be saved then I would be asking for a divine intervention to heal that person. I would hope that you do not pray for me in such a circumstance. You may actually expect a God to step in and fix my problem. Instead, I would want you to have hope as I would. Because that hope that I can be saved should then move you to action, just as it would swiftly move me to action to get you some real help.
Any change in the world is brought about by real action by real people. We obviously fight against the powers of nature and the chaos of the universe, but fight we must if we want anything outside of the status quo. Prayer and hope alone do nothing to change our circumstances.
If a person were wounded you could just watch and hope (or pray) they stop bleeding or you could take action and do something to help them. You can personally try to stop the bleeding and try to get more help. I have seen society step in and help where a supreme being does not.
Doctors have not always existed. Primitive man had no doctor to turn to that could heal the human body. Doctors developed out of a need of society to heal our wounded and sick. If prayer really worked, then we would have had no need to have developed doctors. If there was a God that really listened to us and intervened when asked, then we would have no need for police, firefighters, or any other profession that helps us and protects us from each other and the planet itself.
We have war because we collectively take no action to stop fighting with each other. We have famine because we do not do enough to help feed everyone. We have any number of problems because we have not acted together for the good of society to overcome them. All of the prayers of the planet have done nothing to solve such problems.
Crime does not exist because everyone needs the same religion to guide them. It exists because some selfish people are not working for the good of society. There are plenty of religious criminals that pray they don’t get caught and think they only need their God's forgiveness for their moment of weakness. The only answer to this is that society must take action to punish such behavior. Community-wide prayer will do nothing to reduce crime, but police in the community will work.
Would you rather have prayer from the religious or police to protect you? Would you rather have a doctor heal you or prayers from a billion believers? Would you choose a society of non-theists with doctors, police, and other human intervention or a society of priests that would do nothing but pray for divine intervention for you?
One answer to those questions is that God works through people. That does not help you much if there are no people around to perform God’s work. That rationalization just shows us that it is only the people taking action that matters in this whole scenario. It proves nothing about God’s divine intervention if humans are required to make it happen.
Nature takes action. The physical universe takes action. People can take action. Religion is only belief and hope in the power of prayer and a divine power that should be able to overcome everything else. I prefer to rely on the power of action. It is the only thing I've seen that has ever produced actual results.