Having largely described those seducers, our apostle now comes to exhort those to whom he wrote to beware of them, assuring them that the apostles of Christ, St. Paul, and particularly St. Peter, had expressly foretold of those wicked scoffers that would arise in the church in the last times; which mockers and scoffers he shows were such as without any just cause separated themselves from the church's communion, pretending greatly to sanctity, but addicted to sensuality, and destitute of the Holy Spirit.
Note here, 1. That the scripture speaks much of the sin and sinners that should be found in the latter times; we ought not therefore to be troubled at what is foretold, nor be unarmed when we are so often forewarned. It is a shame for them, who have oft heard and known the doctrines of the apostles, to be surprised by the seducers. St. Jude expects that these Christians, who know what the apostles had delivered, should vigorously oppose all seducers and seduction.
Learn, 2. That a causeless separation from a church of which we are members, is culpable and sinful: a separation from corruptions, and a separation from them that are corrupt, are two distinct things; the former is always a duty, the latter not so.
Learn, 3. That those that separate from the assemblies of the faithful, are unusually sensual, and have not the Spirit; they have not the spirit, either to guide them, or to quicken them, or to comfort them. These are they who separate themselves, sensual, having not the Spirit.