Even though false teachers are able to hide their destructive heresies from the church visible (professing Christians), their immoral lives that are filled with sin (because only someone filled with God’s Spirit has freedom from the dominion of sin Romans 8:17-19) are still in plain sight for all to see.
This was exactly the point Jude was trying to make in his short yet very effective letter, in which he called the church invisible (true Christians) to ardently contend for the faith.
“But these people blaspheme all that they do not understand, and they are destroyed by all that they, like unreasoning animals, understand instinctively. Woe to them! For they walked in the way of Cain and abandoned themselves for the sake of gain to Balaam’s error and perished in Korah’s rebellion. These are hidden reefs at your love feasts, as they feast with you without fear, shepherds feeding themselves; waterless clouds, swept along by winds; fruitless trees in late autumn, twice dead, uprooted; wild waves of the sea, casting up the foam of their own shame; wandering stars, for whom the gloom of utter darkness has been reserved forever.” Jude 1:10-13 ] Read more