Why God Asks Us to Pray
Henry T. Blackaby

It is a serious matter to ask, “Why does God ask us to pray?”
Jesus told His disciples that “... men ought always to pray and not lose heart ... ”(Luke 18:1). Throughout His ministry Jesus was always urging His disciples to pray. But why? Surely, it was not merely for them to get their desired wishes!

Could the answer be found in what we call the Lord’s Prayer? In the middle of Jesus’ Sermon on the Mount, he gives a long and careful word on prayer (Matthew 6:5-15). The heart of it all is His “model prayer,” which begins: “Our Father, who art in heaven, hallowed be Your name. Your kingdom come. Your will be done on earth as it is in heaven....” Examining the text carefully we notice that the heart of prayer is God the Father. Thus, prayer must first focus on God rather than ourselves. Our prayer should be for God’s name and full character to be revealed clearly. We then pray for His will -- not our will -- to be done and that God express His will “on earth” in the arena of our lives. We should desire that heaven’s will be done where we live.

When our prayer is God-centered, God reveals Himself and His heart for all to see. When we pray for God to work mightily for Himself alone, He does. God can then work through the prayer lives of His people to make Himself known to a watching world. And when He does He is glorified! That is, He is seen in His activity for who He is, and this will draw people to Himself. Not all will be "saved," but all will know Him in one way or another. So we must model Jesus' prayer faithfully before we make any request for God to “bless us” and meet our needs.

The rest: http://www.blackaby.org/resources/articles/Pray.asp