I think the song is about a victim of abuse in denial. Her “self-righteous suicide” is sticking by her abuser. She’s justifying her actions to someone by saying, “I don’t think you trust in my self-righteous suicide”… and then the song directly quotes the dying words of Jesus Christ as he despairs of the consequences of his act of sacrifice (the loss of all hope by being separated from God). But then again, this could be mocking Jesus, saying that His crucifixion is “self-righteous suicide”. It’s suicide, yes, but it hella isn’t self-righteous. He was the only one fit to do it, he knew he was supposed to do it and did it, even though he didn’t want to die.