"the biblical purpose of prayer is that we may get to know God Himself."
From the devotional "My Utmost For His Highest" by Oswald Chambers:
... one of His disciples said to Him, "Lord teach us to pray..." - Luke 11:1
"Ask, and you will receive . . ." ( John 16:24 ). We complain before God, and sometimes we are apologetic or indifferent to Him, but we actually ask Him for very few things. Yet a child exhibits a magnificent boldness to ask! Our Lord said, ". . . unless you . . . become as little children . . ." ( Matthew 18:3 ). Ask and God will do. Give Jesus Christ the opportunity and the room to work. The problem is that no one will ever do this until he is at his wits’ end. When a person is at his wits’ end, it no longer seems to be a cowardly thing to pray; in fact, it is the only way he can get in touch with the truth and the reality of God Himself. Be yourself before God and present Him with your problems— the very things that have brought you to your wits’ end. But as long as you think you are self-sufficient, you do not need to ask God for anything.
To say that "prayer changes things" is not as close to the truth as saying, "Prayer changes me and then I change things." God has established things so that prayer, on the basis of redemption, changes the way a person looks at things. Prayer is not a matter of changing things externally, but one of working miracles in a person’s inner nature.