Before you go off listing names of people who you know should be burned with this verse upon their foreheads, assess yourself first. So many times I think that I'm right with God because I know what is right and what is wrong, and I try to follow God's righteous decrees as closely as possible. The truth of the matter is though, that I don't. I can substitute this all the pronouns and replace them with "I" and it would still prove to be a valid statement. "Although I know God's righteous decree that those who do such things deserve death, I not only continue to do these very things but also approve of those who practice them." Rachel 1:32 Makes sense, right? We pick and choose the sins we want to call out upon others yet deny the ones we ourselves commit. That is the essence of self-righteousness and just as dangerous as any other sin.
