Jude 1:3

“"For whosoever does not confess that Jesus Christ has come in the flesh, is antichrist;" and whosoever does not confess the testimony of the cross, is of the devil; and whosoever perverts the oracles of the Lord to his own lusts, and says that there is neither a resurrection nor a judgment, he is the first-born of Satan. Wherefore, forsaking the vanity of many, and their false doctrines, let us return to the word which has been handed down to us from the beginning; "watching unto prayer," and persevering in fasting; beseeching in our supplications the all-seeing God "not to lead us into temptation," as the Lord has said: "The spirit truly is willing, but the flesh is weak."”

“True knowledge, then, consists in the understanding of Christ, which Paul terms the wisdom of God hidden in a mystery, which "the natural man receiveth not," the doctrine of the cross; of which if any man "taste," he will not accede to the disputations and quibbles of proud and puffed-up men, who go into matters of which they have no perception. For the truth is unsophisticated; and "the word is nigh thee, in thy mouth and in thy heart," as the same apostle declares, being easy of comprehension to those who are obedient. For it renders us like to Christ, if we experience "the power of his resurrection and the fellowship of His sufferings." For this is the affinity of the apostolical teaching and the most holy "faith delivered unto us," which the unlearned receive, and those of slender knowledge have taught, not "giving heed to endless genealogies," but studying rather [to observe] a straightforward course of life; lest, having been deprived of the Divine Spirit, they fail to attain to the kingdom of heaven. For truly the first thing is to deny one's self and to follow Christ; and those who do this are borne onward to perfection, having fulfilled all their Teacher's will, becoming sons of God by spiritual regeneration, and heirs of the kingdom of heaven; those who seek which first shall not be forsaken.”

“Here the apostle indicates the motivation for writing the epistle. Namely: he writes the present epistle out of concern for the salvation of the faithful, so that they in their simplicity would not be carried away by the most vile heretics; he writes in order to expose them through a description of the depraved life of the heretics and make them known to those who are unaware. The apostle Peter had already spoken about them, but the apostle Jude writes more extensively. He says that they were "designated beforehand" (v. 4), because the apostles Peter and Paul had already written that in the last times deceivers of this kind would come (2 Pet. 1:1–2, 3:3; 2 Tim. 3:1–8). Even before them, Christ Himself said: "many will come in My name and will deceive many; do not go after them" (Luke 21:8), because by calling themselves Christians, they will deceive many by this name. The apostle speaks of the followers of the most vile Nicholas, Valentinus, and Simon. For being gluttons and intemperate, they gave their teaching a fair-seeming cover in order to gain access to homes and captivate women mired in sins. Having invented certain nocturnal rites, they gave themselves over to debauchery. From this it also follows that they deny our Lord Jesus Christ. For how can those who by their impure life drive away from themselves the Teacher of all chastity not deny Him? For what fellowship has light with darkness? (2 Cor. 6:14).”

“My dearest, I have had such a strong desire to write to you about our common salvation that I could not cease from writing to you: urging you to contend again for the faith once delivered to the saints. For certain ungodly men have secretly entered in, who were long ago marked out for this condemnation: who turn the grace of our God into vileness and deny the only Master God and our Lord Jesus Christ. Through this, the argument of the epistle is hinted at, which, for the providence of their salvation, is now presented to prevent them from being ensnared by the most wicked heretics due to simplicity: it renders their speeches as if marking and making them obvious to the ignorant through the exposure of their lustful lives. Peter also spoke about these matters, but here it is stated more openly and extensively. Jude describes them as abandoned: because both Peter and Paul spoke of those who will be such seducers in the last times. And before these, Christ himself said: "Many will come in my name and will deceive many: therefore do not follow them." (Matt. 24:5) For claiming to be Christians, they deceive many in this name. He mentions Nicholas, Valentinus, and Simon, and those who followed them, the most wicked and impure. For being gluttons and lustful, they pretended to teach, so that under this pretext they might gain a hidden entrance into homes and lead captive women burdened with sins. (2 Tim. 3:6) For they have given themselves over to nighttime mysteries in their beds and lasciviousness (Rom. 13:13). What he says, "They turn to lasciviousness," means that they corrupt themselves, twisting away from abstinence to lasciviousness; therefore they even deny our Lord Jesus Christ. Indeed, how do they not deny Him, who, through the impurity of life, reject the Teacher of all temperance with a vulgar and loud voice? For what unity is there between light and darkness? (2 Cor. 6:14) "urging you to contend again." Jude urges those who have once received Christ the Savior and believed in Him, to continue striving or to endeavor, that is, not to be affected with a disheartened mind, but to contain themselves and embrace even greater zeal regarding this. For we have received the incarnate Word; if we were to say that there is another who was with the Father before the ages, and another who was born in His own hypostasis (ὑπόστασιν) from the Mother in the last times, would we not deny that there is one Lord and Master? For there is one Lord Jesus according to a certain privilege of union. For the Word and God before the ages, having assumed flesh for the glory of divinity, which He received from the divine Virgin from the moment of conception, is one and the same Lord of all. "turn the grace:" that is, they transform, corrupt.”