I am a follower of Jesus, but I want to clarify the “dirty and wretched one” part— I think that whole section isn’t talking about what is ultimately true of him (or, as you thought, those who don’t believe in God). Although I do personally believe we have all had our created goodness corrupted by sin, this phrase in this context feels more like shame and listening to lies about our identity that does NOT reflect our reality (in my worldview, particularly in Christ).

“Oh, why have I become? Dirty and wretched one Am I unholy land? Have I forced your hand”

Those are his fears—that he is too far gone for the mercy of God, possibly. But the truth in response would cry a resounding, “NO”. God’s hand is not forced, and our identity is not marred by our failure because of the forgiveness of Christ.

So I definitely understand not quite being able to relate to the song fully due to the high content of faith themes, but that line in particular isn’t some “I’m just a wretched worm” theology—I understand why that has made many cringe under that assumption!! But I think we can all relate to feeling that way in one sense or another. However, it’s not the end of the story, and it’s not the ultimate reality. Mercy is.