1 Inasmuch, then, as in this world (αἰῶνι) some persons betake themselves to the light, and by faith unite themselves with God, but others shun the light, and separate themselves from God, the Word of God comes preparing a fit habitation for both. For those indeed who are in the light, that they may derive enjoyment from it, and from the good things contained in it; but for those in darkness, that they may partake in its calamities. And on this account He says, that those upon the right hand are called into the kingdom of heaven, but that those on the left He will send into eternal fire for they have deprived themselves of all good.
2. And for this reason the apostle says: “Because they received not the love of God, that they might be saved, therefore God shall also send them the operation of error, that they may believe a lie, that they all may be judged who have not believed the truth, but consented to unrighteousness.” For when he (Antichrist) has come, and of his own accord concentrates in his own person the apostasy, and accomplishes whatever he shall do according to his own will and choice, sitting also in the temple of God, so that his dupes may adore him as the Christ; wherefore also shall he deservedly “be cast into the lake of fire:” [this will happen according to divine appointment], God by His prescience foreseeing all this, and at the proper time sending such a man, “that they may believe a lie, that they all may be judged who did not believe the truth, but consented to unrighteousness;” whose coming John has thus described in the Apocalypse: “And the beast which I had seen was like a leopard, and his feet as of a bear, and his mouth as the mouth of a lion; and the dragon conferred his own power upon him, and his throne, and great might. And one of his heads was as it were slain unto death; and his deadly wound was healed, and all the world wondered after the beast. And they worshipped the dragon because he gave power to the beast; and they worshipped the beast, saying, Who is like this beast, and who is able to make war with him? And there was given unto him a mouth speaking great things, and blasphemy and power was given to him during forty and two months. And he opened his mouth for blasphemy against God, to blaspheme His name and His tabernacle, and those who dwell in heaven. And power was given him over every tribe, and people, and tongue, and nation. And all who dwell upon the earth worshipped him, [every one] whose name was not written in the book of the Lamb slain from the foundation of the world. If any one have ears, let him hear. If any one shall lead into captivity, he shall go into captivity. If any shall slay with the sword, he must be slain with the sword. Here is the endurance and the faith of the saints.” After this he likewise describes his armour-bearer, whom he also terms a false prophet: “He spoke as a dragon, and exercised all the power of the first beast in his sight, and caused the earth, and those that dwell therein, to adore the first beast, whose deadly wound was healed. And he shall perform great wonders, so that he can even cause fire to descend from heaven upon the earth in the sight of men, and he shall lead the inhabitants of the earth astray.” Let no one imagine that he performs these wonders by divine power, but by the working of magic. And we must not be surprised if, since the demons and apostate spirits are at his service, he through their means performs wonders, by which he leads the inhabitants of the earth astray. John says further: “And he shall order an image of the beast to be made, and he shall give breath to the image, so that the image shall speak; and he shall cause those to be slain who will not adore it.” He says also: “And he will cause a mark [to be put] in the forehead and in the right hand, that no one may be able to buy or sell, unless he who has the mark of the name of the beast or the number of his name; and the number is six hundred and sixty-six,” that is, six times a hundred, six times ten, and six units. [He gives this] as a summing up of the whole of that apostasy which has taken place during six thousand years.
3. For in as many days as this world was made, in so many thousand years shall it be concluded. And for this reason the Scripture says: “Thus the heaven and the earth were finished, and all their adornment. And God brought to a conclusion upon the sixth day the works that He had made; and God rested upon the seventh day from all His works.” This is an account of the things formerly created, as also it is a prophecy of what is to come. For the day of the Lord is as a thousand years; and in six days created things were completed: it is evident, therefore, that they will come to an end at the sixth thousand year.
4. And therefore throughout all time, man, having been moulded at the beginning by the hands of God, that is, of the Son and of the Spirit, is made after the image and likeness of God: the chaff, indeed, which is the apostasy, being cast away; but the wheat, that is, those who bring forth fruit to God in faith, being gathered into the barn. And for this cause tribulation is necessary for those who are saved, that having been after a manner broken up, and rendered fine, and sprinkled over by the patience of the Word of God, and set on fire [for purification], they may be fitted for the royal banquet. As a certain man of ours said, when he was condemned to the wild beasts because of his testimony with respect to God: “I am the wheat of Christ, and am ground by the teeth of the wild beasts, that I may be found the pure bread of God.”
Source: Adversus haereses (New Advent)