What's the deal with Prayer?

If your prayer's request is part of God's plan - it will happen whether you want it to or not. If it isn't, then no amount of prayer will provoke it.

Perhaps prayer is for expressing feelings of love only? Except… aren't we dealing with an omniscient being? Does it not, then, always know with 100% accuracy what you know are feeling?

It just doesn't seem to have a role except in the experience of the believer.