Derek's sermon on Psalm 58 explores how Christians should respond to widespread injustice, corrupt rulers, and evil actions in the world. He explains that lament is biblical: believers do not need to pretend everything is fine, but should bring suffering, injustice, and wrongdoing honestly before God in prayer.

He distinguishes lament from grumbling. Lament brings complaint to God in faith; grumbling complains without prayer and can imply giving up on God's goodness or power.

Psalm 58 is then presented as both a lament and an imprecatory psalm—a prayer asking God to restrain or punish evildoers. Derek acknowledges that its violent imagery is difficult for Christians, but argues that much of the language is hyperbolic and aimed at asking God to stop wicked people from continuing their harm.

He then wrestles with the tension between Psalm 58 and Jesus' command to love enemies and pray for persecutors. Derek argues that Christians should love enemies and hope for their repentance, while also taking comfort that God will ultimately judge evil and may rightly be asked to restrain wicked actions now.

The sermon applies Psalm 58 to unjust rulers, false teachers, abusive individuals, and others who harm people through lies, violence, corruption, or abuse. Derek concludes that God notices injustice, cares deeply, and will finally bring justice: punishment for the unrepentant and vindication for those who trust in Christ.