Why do we pray?- I am not speaking of the “transactional” prayers in which types of prayers and sacrifices function as part of the economy of “bargaining” for a divine favor or good fortune from some spirit-god, as shamans, witchdoctors and other “spirit-guides” do.
I am speaking of the appeal that we, finite, mortal and flawed people make to all-powerful and all-knowing, creator and sustainer God.
Back to the question: what is our unspoken or assumed expectation of prayer? I believe it is not only our petition we seek but also by means of the prayer interaction, we wish to experience His immanence in our (little) lives. Yes, we may pray because we seek help, but we also wish for contact with the transcendent—
I have found that the thing most people least understand about prayer is the part about RESULTS. Prayer is efficacious (having the desired result), but beware, in every other pursuit we have a way to measure the desired result. The problem with the efficaciousness of prayer is that God has the measuring stick. If we're using ours (my will, my desired outcome), then the results will appear to be flawed. That should be more than okay with us if God is who He is and we are who we are.
I have had many former church-goers and “universalists” tell me they do not pray because they do not need to. They have a reason: "God is both beneficent and all-knowing, I do not need to pray-without me breathing a prayer, God has read my thoughts and desires and answered them." Theologically this is belief has no legs. But, at its root it’s a problem of pride and laziness (I suspect some people cringe at the humility of prayer). A simple analogy will do to illustrate: both my teenager (and I) know that he needs and wants breakfast before school. Shouldn’t he come to the kitchen for it? If the parent has provided but the child is too lazy to make a move, he’s cutting himself off from the source and will be famihed by lunchtime.
George MacDonald addresses it further in: "Why Should It Be Necessary?”
“But if God is so good as you represent Him [to be], and if He knows all that we need, and far better than we do ourselves, why [is] it necessary to ask Him for anything?”
“What if He knows prayer to be the thing we need first and most? What if the main object in God’s idea of prayer [is] the supplying of our great, our endless need—the need of Himself?
Hunger may drive the runaway child [back] home, and he may or may not be fed at once, but he needs his mother more than his dinner.
Communion with God is the one need of the soul beyond all other need:
prayer is the beginning of that communion, [there is] some need that is the motive of that prayer.
So begins a communion, a taking up with God, a coming-to-one with Him. [This] is the sole end of prayer, [even] of existence itself in its infinite phases.
We must ask that we may receive:[however] it is not God’s end in having us pray to receive with respect to our lower needs [since] He could give us everything without that. [God would] bring us to His knee… [He] withholds [so] that we may ask."
- from George MacDonald, 365 Readings, edited by CS Lewis (language updated) Collier Books, Macmillan Publishing Company, New York.