How do we know that iniquity can have dominion over us?

The psalmist's plea against iniquity having dominion over him illustrates the reality of sin in the believer's life. Iniquity can manifest as habitual sins that we struggle against and which can exert a powerful influence over our thoughts and actions. This prayer reflects the need for God's intervention in our lives to help us overcome these sins and not be ruled by our fallen nature. Through earnest prayer, we seek God's strength to resist the dominion of sin and to walk in righteousness.