You should be compassionate towards people who suffer a relapse.
Dave notices Bill who is a recovering alcoholic drinking beer at the local bar.
Dave wants to make a comment to Bill about drinking.
Dave tells Bill that he knows it's tough to stay away and that he hopes Bill can recover from this.
Dave tells Bill that he's an idiot for relapsing and a no good, useless alcoholic waste of life.
Bill feels good that Dave understands and is optimistic about recovering again.
Bill feels sad and attacked which leads to a deepening depression which eventually causes him to drink even more.