APOSTACY God verbally inspired the Book of Jude to expose apostacy. Those liberals, modernists and neo-evangelicals who ignore false doctrine and ungodliness to teach 'the gospel' need to be warned. Romans 16:17 requires the marking and avoiding of apostates. The preservation of pure doctrine depends on the believer's obedience to God's clear command to fight for the faith. See Jude 3.
Apostacy is a departure from the faith. Apostacy includes a falling way (II Thessalonians 2:3) from revealed truth. Apostates deny the fundamental doctrines of the Bible by word and practice. I Timothy 4:1 has the Holy Spirit warning that the departure will take place in the latter times. These apostates will be given over to "seducing spirits" and "doctrines of devils." Satan will definitely be working his devilish deeds. One only needs to turn over to II Timothy 3:1-13 to verify that we are in the last days. (Every one of the 29 characteristics listed here for the last days matches 1997.)
The nature of an apostate is to creep in. See Jude 4a. When Jesus taught about the end times in Matthew Chapter 24, He mentioned false Christs and false prophets. Apostates have character. How so? They have the character of the "ungodly." Apostates are shameless in their actions. See Romans Chapter 1. When all is said and done, apostates will bend their knee to the Lordship of Christ. Their denial of the Lord Jesus Christ (Jude 4) will be suddenly retracted but it will be too late. Philippians Chapter 2 predicts this. Full blown apostates will receive sure damnation (Jude 5-7).
Apostacy can cost you your family. Remember Lot's situation in Sodom & Gomorrha. Lot's own daughters escaped the city of Sodom, but not Sodom's evils as far as drunkenness and wrong sexual relationships later. We need to separate from wickedness. Our association with apostacy puts our stamp of approval on it. We need to separate ourselves to an extant from those who call themselves Christians but do not live like it. II Corinthians 6:14-17 requires us to evaluate our yokes, fellowship, communion, concord, and agreements. Apostates usually try to explain away the Bible doctrine of Hell. (Mr. Billy Graham is one example of this.)
In Jude 8-10 we find apostates that are immoral, despise authority and love to speak evil of those in authority. Don't be found being a Korah!
In Jude 11 the Bible declares that apostates hate preaching on the Blood. They want their works to count for something like Cain wished, tried and failed. Apostates will nearly always be hypocrites. They won't have any good fruit of the Holy Spirit. See Jude 12. Apostates presently can put on a good 'show' but in the end they will be cast into outer darkness (Jude 13). Apostates walk after their own lusts (Jude 16). They are motivated by greed and materialism. II Peter 2:3 mentions covetousness and the apostate's 'faked' (feigned) words.
The key to overcoming the effect of apostacy is living holy and separated lives, walking daily with the Lord Jesus Christ. Apostates can't endure sound doctrine. Turn up the fire in the Bible preaching and praying, and the apostate will leave. We need to more and more look for Jesus' coming and love Him.