A common question or challenge about prayer is, why tell God what He already knows? If He knows everything, including your every thought and feeling, what's the point in possibly wasting His time by repeating this information to Him?
One assumption people usually have when asking this question is that we have sufficient, if not perfect, knowledge of our own thoughts and feelings. Because we have a front row seat, because they are our own thoughts being thought within our own mind, we think it reasonable to assume that we have the best awareness anyone could have of those thoughts and feelings.
But what occurs to me now is that we don't have the best awareness that anyone could have of our own thoughts and feelings. We are fooled on a regular basis regarding our underlying motivations for doing, thinking, or feeling a given thing. We hide motives and rationales from ourselves on a daily basis.
But God knows. In the physical realm, God maintains in existence every force and subatomic particle in the physical realm, and thus knows in every picosecond the exact location, force, direction, (and probably other characteristics we don't know about) of every one of them. When we give the best account that we can of a given physical situation, God's understanding and utterly immediate awareness of that same situation has an immensity far greater than any we could have. If there exist in the spirit realm the equivalent of atoms, then He also keeps every unimaginably tiny element of that realm in existence by His continual free choice, and knows everything that can be known about that realm as well.
So He knows everything that's happening within us as we move through the chain of thoughts that lead us to offer a given prayer to Him. So even though we feel like we know what we're praying to Him, and out of our ignorance often approach prayer in the same way as we approach telling a human, finite, mortal friend about this or that, He already knows immensely more about what we're talking about than we do. Unless He voluntarily blocks some knowledge from some part of His awareness (if that's possible), it's impossible for us to know more about anything, even what happens within us, than He does.
And so, often God enables the experience of prayer, of our genuine personal encounter with the one true living God, primarily so that we can learn what we really think and feel, who we really are. In prayer we become more of who we really are, especially as we seek and accept His revealing of such things to us.