Our Lord said in Luke 18:1, "that men ought always to pray and not to faint." Prayer is not a mechanical performance to be seen of men, the Pharisees prayed that way and were not heard before God (Matt. 6:5). Prayer is not so much and act as it is a attitude of the heart, and a dependence of the soul upon Almighty God. It is also seeking to spread out our heart's desire before God and asking it to be granted according to His sovereign purpose. Real prayer is communion with God through the only Mediator, Jesus Christ the Lord; who is sitting at God's right hand making intercession for us (Heb. 7:25; 1 Tim 2:5). Prayer is never intended to change the purpose of God, but rather to make us know and realize what the purpose of God is. I have often heard people say, "that prayer changes things." I hope it changes our wrong attitudes, our sinful desires and our ungodly conduct, but prayer never changes the purpose of the eternal God (Isa. 46:9-12). He said, "I am the Lord I change not" (Mal. 3:6).
Well then, since God is sovereign and has decreed all things, then why are we instructed to pray? God has decreed all things, but all He has decreed come to pass through the means He has ordained (Acts 4:27-28). God has elected a people unto salvation (2 Thes. 2:13), but He has also decreed that His people shall be saved from their sin by the appointed means, Jesus Christ; His grace and sacrifice (Rom. 3:24). The gospel then is one of the appointed means to accomplish His eternal purpose and prayer is another. Even the prayers of His people are included in His eternal purpose. Therefore, instead of prayer being useless and vain; they are part of the decrees by which God exercises His eternal purpose. I hope you can all say, "Lord teach us to pray" (Matt.6:9-15).