As Wicked Men Increase

Apostasy is the departure of an individual or a group of individuals from the body of truth they once professed to believe. Apostasy from the truth that God revealed through the prophets, apostles and Christ was well underway shortly after Christ’s ascension into heaven. Writers of the New Testament addressed this matter (I Timothy 2; II Peter 2; Jude, Galatians 1:8).
Such apostasy is the subject of Jude’s epistle. Whereas his intention was to write of the salvation that he and his readers shared in common (v. 3), that purpose was preempted by the presence of apostasy, so that he wrote instead regarding apostates and the response God’s people must make to them.
Jude describes the apostates. First, they turn God’s grace into lasciviousness, or license for immorality. And, they deny our Sovereign and Lord and Savior, Jesus Christ.
For the encouragement of God’s remnant, Jude offered three illustrations from history. This showed that apostasy is nothing new, that God knows how to deal with apostates, and that He is not remiss to do so.