17But you, beloved, ought to remember the words that were spoken beforehand by the apostles of our Lord Jesus Christ, 18that they were saying to you, “In the last time there will be mockers, following after their own ungodly lusts.” 19These are the ones who cause divisions, worldly-minded, devoid of the Spirit. Jude 17-19
If we are truly living in the “last days,” the Bible has its share of warnings for us along the same theme, that “mockers” or “scoffers” will arise who will spread all sorts of doctrines that deviate from the apostles’ teaching. It appears that Jude was on Peter’s mailing list (2 Peter 3:3) as both wrote similarly, using the same word for “mockers.” Paul called these false teachers “salvage wolves” (Acts 20:29) and devoted considerable ink to warning his successor Timothy of the challenges he’d face with these sorts in his ministry. (2 Timothy 3:1-9)
Some thoughts.
First, are we living in the “last days?” Generally, yes. Peter, Jude, Paul, and Timothy technically were, but we, more so some 2,000 years later. The farther we get from the final utterance of Jesus on this earth, the worse it’ll be. In my lifetime, I’ve witnessed a cataclysmic downward spiral, and the pace is quickening as I write this. It’s all head spinning and dusturbing, quite frankly.
Second, where we see divisions in the church, at the root of these will be false doctrine taught by lustful worldly teachers, “devoid of the Spirit.” James, Jude’s brother, calls these teachers and their messages “earthly, natural, and demonic.” (James 3:15)
20But you, beloved, building yourselves up on your most holy faith, praying in the Holy Spirit, 21keep yourselves in the love of God, waiting anxiously for the mercy of our Lord Jesus Christ to eternal life. Jude 20-21
Knowing these truths, Jude writes to his beloved, to those who possess a common salvation, to keep building up their core strength, that is, their most holy faith. Not particularly their trust in the Lord, but all the crucial elements of their Christian faith, two of which are praying in the Spirit, as only we can do as Christians, as one commenter puts it, “with watchful care keeping yourselves within the sphere of God’s love,” and waiting expectantly for the Lord’s merciful strong right hand, which will ultimately lift us into eternity.
6 Now I know that the Lord saves His anointed; He will answer him from His holy heaven with the saving strength of His right hand. Psalm 20:6
At the Gate 
Elephant in the Room
It’s been interesting to observe which preachers have paused their sermon plans, even briefly, for important straightforward biblical teachings to address the state of advancing and unrestrained evil in the world, in our nation, in our cities, and in some cases, in our churches.
Some have kept their noses to the theological grindstone. Others have opted for messages on love and acceptance, tiptoeing to find something “socially” acceptable to say from the pulpit. Then there are those who focus almost exclusively on the “end of the world,” to the point their congregations are “no earthly good.” Indeed, it’s a veritable minefield out there if one worries about stepping on any toes, one way or another.
In a way, Jude faced this dilemma when he sat down to write about “our common salvation,” but interestingly, “felt the necessity” to switch gears. With the same, or perhaps extra added effort due to the urgency of the matter, he implored his audience to “contend earnestly” for the faith, as would a “combatant.” The word “earnestly,” by the way, is added to intensify the exhortation.
Jude recognized that the faith that was “once and for all handed down” was in danger of contamination or dilution to the point of ineffectiveness. From day one, Satan has tried everything to obfuscate the truth, and the church and its messengers have been his primary targets.
This short letter helps us to navigate in an “ungodly” world, woefully defiled, increasingly devoid of truth and sanity, in denial, while at the same time attempting to reach it (v. 20-23, more on this later).