Verse 4. For if God spared not the angels that sinned. The apostle now proceeds to the proof of the proposition that these persons would be punished. It is to be remembered that they had been, or were even then, professing Christians, though they had really, if not in form, apostatized from the faith, (2 Pe 2:20-22;) and a part of the proofs, therefore, are derived from the cases of those who had apostatized from the service of God. He appeals, therefore, to the case of the angels that had revolted. Neither their former rank, their dignity, nor their holiness, saved them from being thrust down to hell; and if God punished them so severely, then false teachers could not hope to escape. The apostle, by the angels here, refers undoubtedly to a revolt in heaven -- -an event referred to in Jude 1:6, and everywhere implied in the Scriptures. When that occurred, however -- why they revolted, or what was the number of the apostates -- we have not the slightest information, and on these points conjecture would be useless. In the supposition that it occurred, there is no improbability; for there is nothing more absurd in the belief that angels have revolted than that men have; and if there are evil angels, as there is no more reason to doubt than that there are evil men, it is morally certain that they must have fallen at some period from a state of holiness, for it can not be believed that God made them wicked.

But cast them down to hell. Gr., tartarwsav -- "thrusting them down to Tartarus." The word here used occurs nowhere else in the New Testament, though it is common in the classical writers. It is a verb formed from tartarov (Tartarus,) which in Greek mythology was the lower part, or abyss of hades, where the shades of the wicked were supposed to be imprisoned and tormented, and answered to the Jewish word geenna -- Gehenna. It was regarded, commonly, as beneath the earth; as entered through the grave; as dark, dismal, gloomy; and as a place of punishment. Comp. See Barnes "Job 10:21,22, and See Barnes "Mt 5:22".

The word here is one that properly refers to a place or punishment, since the whole argument relates to that, and since it cannot be pretended that the "angels that sinned" were removed to a place of happiness on account of their transgression. It must also refer to punishment in some other world than this, for there is no evidence that this world is made a place of punishment for fallen angels.

And delivered them into chains of darkness. "Where darkness lies like chains upon them." -- Rob. Lex. The meaning seems to be, that they are confined in that dark prison-house as if by chains. We are not to suppose that spirits are literally bound; but it was common to bind or fetter prisoners who were in dungeons, and the representation here is taken from that fact. This representation that the mass of fallen angels are confined in Tartarus, or in hell, is not inconsistent with the representations which elsewhere occur that their leader is permitted to roam the earth, and that even many of those spirits are allowed to tempt men. It may be still true that the mass are confined within the limits of their dark abode; and it may even be true also that Satan and those who are permitted to roam the earth are under bondage, and are permitted to range only within certain bounds, and that they are so secured that they will be brought to trial at the last day.

To be reserved unto judgment. Jude 1:6, "to the judgment of the great day." They will then, with the revolted inhabitants of this world, be brought to trial for their crimes. That the fallen angels will be punished after the judgment is apparent from Re 20:10. The argument in this verse is, that if God punished the angels who revolted from him, it is a fair inference that he will punish wicked men, though they were once professors of religion.