Lyric discussion by Plans 

Cover art for Hallelujah lyrics by Panic! at the Disco

I think this song is simply about accepting yourself, no matter how bad or 'sinful' you might be or what you've done in the past. Acceptance means not just being comfortable with yourself, but also being able to face the fact that you've made mistakes and you need to fix them and make up for them. Brendan said it's about "taking responsibility for things that you felt guilty for in the past and just owning it because now that’s a piece of you, and you can’t get rid of that history". It sums up the song pretty well- being able to stand up and say 'Hallelujah" despite everything that's happened because you still have a chance to change yourself.

My Interpretation

@Plans well look at the second verse especially. brendon said that it was about the words he said drunk and he is apologizing for them. this proves your theory