When we are surrounded by lies, we need to be reminded of the truth.  Otherwise, we risk being pulled away from Jesus and becoming a spiritual danger to others (Acts 20:29-30).  Jude knew that his readers had believed the true apostolic gospel, but false teachers were luring some away to satisfy their own fleshly appetites (Jude 1:3-4).  So, Jude reminded them that their faith was not a nice idea to bring comfort while they pleased themselves, but a potent call to radical life-change - so that they could say ‘No’ to wickedness and ‘Yes’ to righteousness (Titus 2:11-14).