

In this Psalm David, the author, is clearly an expression of grief and sorrow for something that is going on in his life. He considers his antagonists are also enemies of God.
He begins with a terse statement which includes an appeal for help and the complaint against his enemies. He says his enemies, people to whom he has shown goodness and love, have lied and slandered him, and God has been silent through all of this.
He then asks for retribution. The picture that David paints is a court of law in which a wicked person (the accuses) is to be judged. He details the sentence the accused deserves.
- Let him be found guilty
- Let his prayer be counted as sin
- Let his days be few
- Let someone else take his position
- Let his children be fatherless ending his lineage as if he had never existed
- Let his wife become a widow
- Let his children become homeless beggars, with no one caring for them
- Let him lose all his material possessions
- Let his sin never be forgotten even by God
David ends with a prayer for deliverance. He prays that God will have mercy on him, and vindicate him, so that his enemies realize that God's hand has delivered him. He ends confident that even in this trouble he will have opportunity to praise God for answered prayer.
But I Thought God Was All About Love
We Christians have trouble reconciling this and other Psalms in which the author prays that God destroy their enemies along with their families, often in very graphic ways, with a God who we describe as love who calls us to love even our enemies.
1 John 4:8 (NKJV)8 He who does not love does not know God, for God is love. 8 The one who does not love does not know God, because God is love.
Matthew 5:44 (NKJV)44 But I say to you, love your enemies, bless those who curse you, do good to those who hate you, and pray for those who spitefully use you and persecute you,
The message of the Gospel is that the vengeance for which the psalmist, and we often pray is not on us. Jesus came to the earth to take upon Himself our sins and our punishment. God placed upon His Son the punishment which David petitioned God to bring upon his enemies. No one who places his trust in the solution to sin—the Savior, Jesus Christ—need suffer the consequences of sin. It is only those who resist and reject God’s solution who suffer His temporal and eternal wrath. The psalmist who prayed for God’s justice for his enemies also petitioned God for His mercy and loving kindness. God offers mercy and forgiveness to all, but He also promises justice and judgment to all who reject His Son. I encourage you to place your trust in Jesus Christ, the sin-bearer who died in your place and suffered even more than Psalm 109 describes. From Psalm 109: A Prayer for the Punishment of the Wicked
Romans 12:19-21 (NKJV) 19 Beloved, do not avenge yourselves, but rather give place to wrath; for it is written, "Vengeance is Mine, I will repay," says the Lord.20 Therefore "If your enemy is hungry, feed him; If he is thirsty, give him a drink; For in so doing you will heap coals of fire on his head."21 Do not be overcome by evil, but overcome evil with good.