Prayer vs. Command

My understanding of the reason for prayer, in addition to worshipping God and thanking him, is to bring us into his presence, to conform our will to his, to petition him on our behalf or others’. But if you read some of the prayers in our Episcopal Book of Common Prayer with an analytical and critical eye, or listen to folks as they pray aloud, it sounds as though we’re commanding him to do our will. “Heal...!” “Give us...!” “Lead us...!” “Bless...!” “Make...!” The words seem to convey that we’re trying to order the Great Architect of the Universe to perform—to conform —to our specifications. Do we regard God as a marionette, and consider ourselves puppeteers who can get God to do what we want, not by moving our hands, but by simply opening our mouths? Are we so arrogant as to believe that we can change his mind?
On the other hand, does He really change the natural course of events—even cause miracles to happen—in response to our heartfelt utterances? Well-documented spiritual healings and otherwise unexplainable changes in physical circumstances seem to support this. Would these things have happened anyway??
Centuries of theologians have pondered these questions; I suspect each of us must come to his own understanding of prayer. No matter how or why God answers our prayer, even if He says “No” or “Wait,” the fact that He does cannot be doubted. I suppose the most convincing reason that we should pray is that He told us to. He never guaranteed which results would transpire, only that they would conform to his will. Our job is simply to pray!