"Father, if you are willing, take this cup from me; yet not my will, but your will be done." - Luke 22:42
"Prayer is designed more to adjust you to God, than to adjust God to you and your desires." - Oswald Chambers
Some of the keys to a powerful prayer life are revealed in the verses above. Jesus' life here on earth was a great example for us to follow. A Christian's prayer life will be powerful and his/her life will be fruitful when the personal relationship and fellowship with the Lord is similar to Jesus' relationship with God. His life and His relationship with God was marked with reverent submission, obedience, a servant's heart, and a great love & passion & devotion for God.
Jesus was fully committed to seeking and doing God's will above His own, and to honoring and glorifying God. Whenever Jesus needed to accomplish something, He prayed and sought God's will and wisdom. Sometimes He prayed all night (see Luke 6:12-13). And because of His close and unbroken fellowship with God and His reverent submission, He was always heard by the Father. May we have such relationships and fellowship with the Lord.