Although I discussed the absurdity of petitionary prayer in my original essay against the Catholic faith, I have never written nor read anything about one particular aspect of this type of prayer:
Almost every petitionary prayer is a prayer for a literal miracle.Petitionary prayer is prayer in which a person asks something of a deity, as distinguished from prayers of thanksgiving and meditative prayers. And it almost always asks for a supernatural, physical miracle. Sometimes this is obvious, such as when someone prays for a miracle cure from an illness, but believers never seem to realize they are always asking the laws of nature to be broken on their behalf. Let's examine a simple example, perhaps the most common type of petitionary prayer: a person asks God to bless them or someone else and keep them healthy. All diseases and injuries have physical causes whether it be bacteria, viruses, genetic defects, radiation, etc. When someone prays for health, they are asking that these physical causes not have the negative effect they would have had, or for their medical treatments to have a positive effect they wouldn't have had, if the prayer had not been said. For a deity to answer this prayer, it must somehow intervene on a physical level and alter the laws of nature. Even to inspire the person to healthier lifestyle, it must alter the neurons inside the person's head, again necessitating a literal miracle. Citing “spiritual” or “mystical” effects is absolutely meaningless because they can't effect physical substances without having a miraculous physical effect. If someone prays for a safe road trip, they are asking for the weather to miraculously change or for their equipment to miraculously function properly or for drivers to miraculously pay better attention. Even deities cannot give you a safe trip without doing anything.
The only type of petitionary prayer that doesn't seek a miracle is one that asks for something spiritual. If one asks a deity for forgiveness, the granting of mercy wouldn't entail any physical miracle. Even in this case, however, a miracle would be necessary to know that the mercy was granted, so even asking to feel forgiven is asking for a physical miracle, too.
I would like to end with a paraphrased quote by another user at an online forum which doesn't fit my theme perfectly but which is topical enough and which I found hilarious: “If prayer were sent by e-mail, you'd get a message back from your mailer daemon!”