A look at the parallels between sinners and smokers.
No one stinks like a smoker does. It’s true, and what’s more, they don’t realize how bad they smell. The reason they smell so poorly is that they have deadened the sensitivity of their nose. They literally can’t smell the stench that a non-smoker can smell.
The conscience is like a nose. It sniffs out the stench of sin. Someone who has deadened the sensitivity of his conscience literally can’t detect how morally bad he is. That’s why we need God’s Law. It stirs the conscience so that it can detect sin. When the conscience does its bloodhound duty, it shows us that we don’t smell like a rose, but that even our very best deeds stink (for want of a better word) to high Heaven. Check out Isaiah 64:6 and Romans 3:10-20 to sniff out more details.