Jude 1:10

But these speak evil of those things which they know not The context leaves no doubt that the region of the "things which they know not" is that of good and evil spirits. The false teachers were, though in another spirit, "intruding into those things which they had not seen," like those whom St Paul condemns in Colossians 2:18.

but what they know naturally, as brute beasts There is an obvious reference to the natural impulses of sensual desire which the false teachersdid understand only too well, but which they perverted either to the mere gratification of lust, or, as the words and the context seem to indicate, to that gratification in a manner which was contrary to the laws of nature. If we would understand the burning vehemence of the writer's language, we must picture to ourselves the horror which he would feel at finding sins like those of Romans 1:26-27 reproduced among those who claimed to be followers of Christ, transcending others in their knowledge of the mysteries of the faith.