Summary: King David takes us to the heart of prayer. David shows us a repentant heart, a trusting heart, and a longing heart.
Understanding that basic fact about prayer sheds some light on David’s words. From the beginning of the Psalm to the end he bases his prayer on God’s mercy, faithfulness and righteousness. David used God’s covenant Name, “LORD,” four times in the Psalm. We hear phrases like, “your unfailing love,” “for your name’s sake,” “in your righteousness,” and “in your unfailing love.” Do you see the foundation upon which David built his prayer? The heart of David’s prayer is a repentant heart. He fully acknowledged that the only reason God had for answering his prayer was because of God’s mercy, faithfulness, and love. It is because God had forgiven David sins and brought him into a covenant of grace that he would hear his prayers.
As we learn the heart of prayer from David we quickly see that prayer calls for a repentant heart. Our sinful nature thinks it can walk proudly into God’s presence and demand that he listen. Such prayers don’t acknowledge the plain truth that our sins separate us from God. Isaiah worded it well when he wrote, “But your iniquities have separated you from your God; your sins have hidden his face from you, so that he will not hear.” (Isaiah 59:2 (quickview) ) Or maybe our prayers have been deadened by a different problem. Satan has convinced us that God only hears the prayers of those who are good and behave decently. Then we fail to pray because we don’t think God will listen to us. In either case we need to come back to the truth about why God listens to our prayers. It is only because of his mercy and love shown us in Christ.
In his Small Catechism Martin Luther described the wonderful truth about why God answers our prayers. In his explanation of “The Fifth Petition,” which is “And forgive us our trespasses as we forgive those who trespass against us” he wrote, “We pray in this petition that our Father in heaven would not look upon our sins or because of them deny our prayers; for we are worthy of none of the things for which we ask, neither have we deserved them, but we ask that He would give them all to us by grace; for we daily sin much and surely deserve nothing but punishment.” That describes the heart of prayer; it is a repentant heart.
But a repentant heart will be left in despair if it doesn’t find forgiveness in the blood of Christ. David looked ahead with the eyes of faith to the time when the Savior would come. He based his confidence in prayer on God’s undeserved love for sinners that would be revealed through that Savior. We look back with eyes of faith to the cross of our Savior. The suffering and death of Jesus opened God’s ears to our prayers. That is why we now pray in Jesus’ name. We are saying to our Heavenly Father that it is only because of Jesus that he should listen to our prayer. Hebrews 4:16 (quickview)  gives us this encouragement, “Let us then approach the throne of grace with confidence, so that we may receive mercy and find grace to help us in our time of need.” And Ephesians 3:12 (quickview)  adds this thought, “In him and through faith in him we may approach God with freedom and confidence.” The throne of God is a throne of grace from which the answers to our prayers flow when we find our righteousness in Christ alone.