Because of their attachment to sensual pleasures, the heretics will find their recompense in those very pleasures. "By what a man sins, by this he is punished," says the Wise One (Wis 11:17; cf. Gal 6:8).
Thus, in their very corruption, the heretics will bear punishment through their bodily and spiritual decay. Besides this, they will receive divine recompense for their contempt of the law.
The death of sinners is cruel, but their further lot is still more grievous. "Depart from Me, you cursed," that is, those already appointed to destruction by the laws previously spoken, "into the eternal fire prepared for the devil and his angels" (Mt 25:41). So the future Judge will say to them.
The question arises: how could such sinners appear among the earliest Christians (cf. Jas 2:1-4; Jas 4:1-4)? But the apostle has disclosed with sufficient fullness and clarity the grounds and conditions that favored their corruption.
The chief cause is apostasy from the Christian faith and a return to the former principles of life. This gave the apostle occasion to express his deep lament over them further on.