In Psalm 18 David celebrates the work of the Lord in delivering him from all his enemies. These enemies were primarily the nations around Israel but also included Saul. Because David was an Old Testament foreshadowing of Christ, his victories exemplify the victories of our Lord Jesus Christ over our enemies, both demonic and human. That’s one way we can see Christ in this psalm, but it’s not the only way. At the end of the Psalm David looks to the future: “Great deliverance He [the LORD] gives to His king, / And shows mercy to His anointed, / To David and his descendants forevermore.”
There are several themes in the psalm which apply to Christ. David begins with love for the Lord: “I will love You, O LORD, my strength.” He describes his prayer: “In my distress I called upon the LORD.” He remembers the Lord’s answer: “Then the earth shook and trembled… He sent from above, He took me; He drew me out of many waters.” He explains the Lord’s reasons for delivering him: “The LORD rewarded me according to my righteousness.” He praises God for strength to fight: “For by You I can run against a troop, / By my God I can leap over a wall.” He recounts victories won: “You have also given me the necks of my enemies, / So that I destroyed those who hated me.” And he gives thanks for the subduing of peoples under him. All of these can apply to our Lord Jesus Christ as well. This is his song as much as it is David’s.
But David also remembers God’s covenant with him (2 Sam. 7 and Ps. 89) and the promise that he would have a son to sit on his throne forever. He speaks directly of his descendants to whom the Lord will show mercy forevermore. The word that the NKJV translates as descendants is a singular collective noun in the Hebrew; a better translation would be “seed” or– since that particular use of the word “seed” is not well-known today–“offspring.” As the apostle Paul points out the singular is important. It teaches us that the seed of Abraham is essentially one: our Lord Jesus Christ (Gal. 3:16). David had many sons who sat on his throne after him, but they were important only as ancestors of Jesus (cf. Matt. 1:1-17).
The Lord gave deliverance not only to David but to Christ. To him, and to those who are in him, he continues to show an everlasting mercy. Thus, in Christ, we celebrate with David by the words of this song what God has done for us in his Anointed, the one who even now sits at his right hand. “The LORD lives! Blessed be my Rock! / Let the God of my salvation be exalted.” Jesus is the God of our salvation, and after he has subdued all our enemies, we will live and reign with him forever.