In Ecclesiastes 6:6, the phrase a thousand years is associated with a human lifetime: “Yea, though he live a thousand years twice told, yet hath he seen no good: do not all go to one place?” In the Psalms, a thousand years is compared to yesterday when it is past, and a watch in the night, concepts which might apply metaphorically, or spiritually, to a lifetime. “For a thousand years in thy sight are but as yesterday when it is past, and as a watch in the night.” [Psalm 90:4] The number a thousand is used in Scripture to indicate an indeterminate quantity, and completeness or fullness. “For every beast of the forest is mine, and the cattle upon a thousand hills.” [Psalm 50:10]
In Revelation 20, where Satan is bound for a thousand years, and those who are beheaded reign with Christ for the same period of time, the thousand years may be understood as a symbol of the duration of the believer’s new life in Christ. When a person believes the gospel, and is baptized, he or she is raised up, as Jesus was, in newness of life. Paul said, “Therefore we are buried with him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life.” [Romans 6:4]
Paul said the believer has been blessed with spiritual blessings in heavenly places. [Ephesians 1:3] This new life is one of reigning with Christ, and Paul described the saints as sitting together “in heavenly places in Christ Jesus.” [Ephesians 2:5-7] These teachings mean believers are “raised up” and have received “new life” of a spiritual kind, and in Revelation 20, John incorporates these ideas in his prophecy, where the concepts of a thousand years, reigning with Christ, resurrection, gaining victory over the beast and his image, and the binding of Satan are all spiritual ideas related to our Christian experience. They apply to believers individually. The thousand years is symbolic of the remaining time allotted to each of the saints. It should not be taken literally.
John also includes the idea that the saints who reign with Christ have been beheaded. This is a metaphor representing submission of ones’ mind to God. Paul exhorted the saints to become living sacrifices: “I beseech you therefore, brethren, by the mercies of God, that ye present your bodies a living sacrifice, holy, acceptable unto God, which is your reasonable service.” [Romans 12:1] James said, “Submit yourselves therefore to God. Resist the devil, and he will flee from you.” [James 4:7]
If the meaning suggested above for the thousand years is correct, what happens when the thousand years come to an end? If the thousand years of Revelation 20 are understood in a spiritual sense, rather than by the letter, and it represents the duration of the lives of individual Christians as explained above, the thousand years ends prematurely for those who fall away, who abandon their faith, who return to the world from which they had escaped, and cease to walk in the way of Christ, thus terminating the thousand years, which represents the duration of their reign with Christ. For them, the thousand years are finished.
The thousand years ends prematurely for those who are seduced, and follow the tail of the dragon, as pictured by stars that are cast to the earth in Revelation 12:4.
On the other hand, those who endure to the end receive a “crown of life.” James wrote, “Blessed is the man that endureth temptation: for when he is tried, he shall receive the crown of life, which the Lord hath promised to them that love him.” [James 1:12; see also Revelation 2:10] John said, “Blessed and holy is he that hath part in the first resurrection: on such the second death hath no power, but they shall be priests of God and of Christ, and shall reign with him a thousand years.” [Revelation 20:6]
John connects an assault upon the camp of the saints and the beloved city by deceived people from all parts of the earth, the hordes of Gog and Magog, with the termination of the thousand years.
Augustine of Hippo applied the thousand years of Revelation 20 to the church as a whole, rather than to individual saints. He wrote: 
Chapter 11.–Of Gog and Magog, Who are to Be Roused by the Devil to Persecute the Church, When He is Loosed in the End of the World.
“And when the thousand years are finished, Satan shall be loosed from his prison, and shall go out to seduce the nations which are in the four corners of the earth, Gog and Magog, and shall draw them to battle, whose number is as the sand of the sea.” This then, is his purpose in seducing them, to draw them to this battle. For even before this he was wont to use as many and various seductions as he could continue. And the words “he shall go out” mean, he shall burst forth from lurking hatred into open persecution. For this persecution, occurring while the final judgment is imminent, shall be the last which shall be endured by the holy Church throughout the world, the whole city of Christ being assailed by the whole city of the devil, as each exists on earth. For these nations which he names Gog and Magog are not to be understood of some barbarous nations in some part of the world, whether the Getæ and Massagetæ, as some conclude from the initial letters, or some other foreign nations not under the Roman government. For John marks that they are spread over the whole earth, when he says, “The nations which are in the four corners of the earth,” and he added that these are Gog and Magog.
The Church is in all parts of the earth, and those who are deceived by Satan turn against believers who are faithful. Augustine continued:
The words, “And they went up on the breadth of the earth, and encompassed the camp of the saints and the beloved city,” do not mean that they have come, or shall come, to one place, as if the camp of the saints and the beloved city should be in some one place; for this camp is nothing else than the Church of Christ extending over the whole world. And consequently wherever the Church shall be,–and it shall be in all nations, as is signified by “the breadth of the earth,”–there also shall be the camp of the saints and the beloved city, and there it shall be encompassed by the savage persecution of all its enemies; for they too shall exist along with it in all nations,–that is, it shall be straitened, and hard pressed, and shut up in the straits of tribulation, but shall not desert its military duty, which is signified by the word “camp.”
Augustine’s interpretation was challenged in the fourteenth century by John of Rupescissa, a French alchemist, and a Franciscan, who was influenced by the teachings of Joachim of Fiore, and Peter Olivi; he claimed that the thousand years of Revelation 20 means a literal millennium of a thousand years.
Also known as Giovanni da Rupescissa, John of Roquetaillade, Jean de Roquetaillade, Rupescissa studied for five years at Toulouse, after which he entered the Franciscan monastery at Aurillac. His experiments in distillation led to the discovery of aqua vitae, or alcohol, usually prepared by distilling wine.
Rupescissa’s interpretations of prophecy, together with his denunciation of ecclesiastical abuses, led to accusations of heresy by his superiors in the Franciscan order. He suffered imprisonment in 1344, in various Franciscan convents. After five years, his case was presented at the papal court at Avignon. He was eventually declared orthodox, but insane. He was detained at Avignon and remained there for the rest of his life. He produced several books about prophecy in which he explained his view of the millennium.
In Liber secretorum eventuum, Rupescissa taught that the millennium would be characterized by the conversion of the Jews, a joint government of the world by a papal-imperial partnership, and proliferation of spiritual insight, ecstatic contemplation, and evengelical sanctity.  Rupescissa said converted Jews would replace the Romans as God’s chosen imperial nation. His biographer Robert E. Lerner wryly commented, “the assignment of world government to a reviled people was surely an act of the imagination.”
As well, a governmental center would be “located in a splendidly rebuilt but unfortified Jerusalem;” a holy pope … would reign from this center; seven ecumenical councils would dispose over matters concerning the pope; a ‘collegium ecclesie’ — a college of cardinals, would remain in Jerusalem to the end of time. The great Jewish Emperor, reigning in concert with the pope, would reside near Jerusalem, rather than in the city itself, because the millennial clergy was not to be ‘polluted’ by secular men. The Franciscan order would become the most evangelically perfect among the clergy; the Holy Spirit would descend in such plentitude upon the entire world that it would seem for all ‘as if paradise had descended to earth.’ Lerner wrote: “The cardinals surely knew that Rupescissa was teaching suspect doctrine, and far from silencing him they permitted him to continue writing, and far from preventing the circulation of his writings they passed these around so freely that his predictions were soon coursing through Europe.” 
Rupescissa found it was necessary to say there would be two Antichrists; the first one, he said, would appear in the year 1365 A.D., and continue for three years and a half. This date was calculated by taking the 1,290 days of Daniel 12:11 as so many years, a period which he thought began in 75 AD, when he supposed the Jewish temple was destroyed. Rupescissa encouraged violence in the struggle against the Antichrist. In 1356 he wrote Vade mecum in tribulatione — Go with me in trouble. Peter Olivi had said the millennium would last for 700 years; John of Rupescissa said the time between Antichrist and the last judgment would be 1000 years, which he based on Revelation 20. The thousand years when the martyrs would reign on the earth would ultimately end in the revolt by the hordes of Gog and Magog, the second Antichrist. Rupescissa said: 
It is evident what [Scripture] says about the martyrs at the time of Antichrist that “those who adored neither the beast nor his image, etc.” will live resurrected in their bodies and reign corporeally with Christ for one thousand years, which will be from the time of the death of Antichrist until the advent of Gog near the end of the world. The resurrection of the body does not include all of the saints and martyrs of other times, but is the exclusive mark and privilege of the martyrs of the time of Antichrist. This is why one finds rightly that “the rest of the dead will not live until the one thousand years pass”–counting from Antichrist’s death and the chaining of the dragon until the advent of Gog and the end of time and the world.
Rupescissa connected the chaining of Satan with the death of the Antichrist. That may seem plausible, but a spirit cannot be bound by a literal chain, however strong and heavy it may be. Rupescissa wrote: 
One must note that if Augustine had been obliged to give a symbolic explanation of the one thousand years, he had not been given the understanding that the chaining of the of the dragon has to take place on the day of Antichrist’s death, as one sees manifiestly in De civitae Dei. Moreover, we are not held to follow the explications of all of the doctors in all points; they have advanced them as conjectures rather than as facts asserted against the truth of the text. The obligation holds only if one can prove from sacred text or from some determination of the church that all the secrets of the scriptures and of prophecies have been completely revealed to Augustine and the rest of the doctors of past times in such a way that nothing more must be revealed to those who follow. But Gregory, the most esteemed doctor, says the opposite in his homily nine on Ezekiel. He teaches there that people who live later and are closer to the end of the world will understand in a manner more luminous and clear the hidden truths of holy scripture.
Leah DeVun commented: 
Rupescissa’s claim that those who lived closer to the end of time would comprehend Scripture better than previous church authorities is crucial. He thought himself to be at a more advantageous position in time than Augustine and, as a result, he felt free to overturn the saint’s interpretation regarding the millennium. Rupescissa next dismissed those who believed that the period after Antichrist would endure a mere forty-five days, noting that the saints claimed only that that would be its minimum duration. In a few spirited paragraphs, Rupescissa summarily dispatched the pronouncements of both Augustine and Jerome, which had been the basis for hundreds of years of apocalyptic exegesis. Moreover, Rupescissa referred to this period as the “third state” in the Vade mecum, linking his millennial age to Joachim of Fiore’s trinitarian division of history.
Rupescissa was no doubt influenced by the calculations of his predecessors, and he incorporated their numbers into subsections within his millennium. Rupescissa predicted that after Antichrist’s defeat, wars and other trials would rage for forty-five years (Arnald of Vilanova’s number) until the peace was finally instituted. After the peace had endured for seven hundred years (Peter Olivi’s number), the sanctity and stability that characterized the millennium would begin to deteriorate: the clergy would slide into pride, gluttony, and corruption, justice would vanish, and the truly saintly would become objects of derision. This period of decline would usher in the final stand of Gog, Magog, and the last Antichrist, which would immediately precede the last judgment.
Below, DeVun describes Rupescissa’s concept of the millennium: 
The infidels will convert to Christianity, save a small number who will scatter to the far reaches of the globe. In what has been described as one of the “most concrete philo-Judaic predictions issued by any Christian until this time,” Rupescissa claims that the converted Jews will become God’s chosen people and will wield power over the entire earth. Although Rupescissa speaks a great deal of conversion, the Vade mecum predicts the destruction of the Muslims during the period of tribulations. Rupescissa makes a similar prediction in Liber ostensor, which describes the annihilation of the Muslims as a precursor to the final age of renovation and peace. Rupescissa’s prediction of the destruction of Islam was not an especially common view in the fourteenth century. The astrologer Jean de Murs offered a similar forecast in his nearly contemporary letter to Clement VI on planetary conjunctions, and because Rupescissa was familiar with the writings of Murs and other contemporary astrologers, he may have been influenced by the same climate of anti-Muslim sentiment. Nevertheless, Rupescissa departs from the opinions of apocalypticists such as Arnald of Vilanova and Rampon Llull, who strongly preferred the conversion of the Muslims to their destruction and who advocated missions by Franciscans familiar with the languages and arguments of non-Christians, a prospect that seems to interest Rupescissa not at all.
… His attitude toward Islam appears to be another facet of Rupescissa’s predilection for radically removing what he perceived to be diseased extremities from the larger organism of humanity.
Rupescissa claims that all human beings who survive will receive illumination from the Holy Spirit after Antichrist, yet hierarchies of spiritual and social ranking will not vanish from society. A universal emperor and a pontiff (now centered in Jerusalem) will continue to rule over the people.
Rupescissa employed prophecy in his efforts to reform the Church in his own age, but he did not comprehend the true meaning of those prophecies. His interpretations of the thousand years of Revelation 20, and the 1,290 days of Daniel 12:11 were wrong. The 1,290 days are not 1,290 years as he assumed; neither is the thousand years meant literally, as 2 Peter 3:8 warns us. The events Rupescissa predicted for 1365-1370 failed to happen, and similarly his interpretations of the thousand years, and the Gog and Magog assault upon the saints, were flawed. There are not two antichrists; neither is the Antichrist a single individual. John spoke of the spirit of antichrist. John’s prophecy in Revelation 20 must be understood spiritually, and interpreted in the light of scripture. In turn, John interpreted Ezekiel’s prophecy as a spiritual invasion, and an assault upon the church by those who are deceived. Those who insist on a literal millennium, following Rupescissa, misunderstand John’s prophecy. The thousand years for which the saints reign with Christ is a spiritual concept, and literal earth years and months don’t apply to it. And the 1,290 days, as part of the time, times and a half, the last part of the 70th week in the prophecy of Daniel 9:24-27, in which Christ confirms his covenant with many, and builds his church, is symbolic time; units of earth days, earth months, and earth years do not determine the extent or duration of the remaining half-week when the heavenly Jerusalem is completed by God, the city built without hands.
1. St Augustine. City of God. Book 20, 11.
2. Johannes de Rupescissa, Robert E. Lerner, Christine Morerod-Fattebert. Liber secretorum eventuum. p. 83.
4. Leah DeVun. Prophecy, alchemy, and the end of time: John of Rupescissa in the late Middle Ages. Columbia University Press, 2009. pp. 38-39.
5. Ibid., p. 39.
6. Ibid., p. 39-40.
7. Ibid., p. 43.