This song is theologically rooted in 2 Corinthians 12 where Paul describes his frustrating experience of trying to be strong and perfect, only to fail repeatedly. In the letter Paul turns to God, and is surprised that God doesn’t take away his problems, but says, “My grace is sufficient for you, for my power is made perfect in weakness.”

The song is about the singer experiencing the same thing for herself. She is frustrated with her failures (especially moral failures, since they leave her “filthy”), and finds her own efforts to do better are self-defeating. The chorus is the same conclusion that St. Paul comes to: we are “perfect in weakness”, and perfect in [God’s] strength alone.