"Let no one in any way deceive you, for it (the Day of the Lord) will not come unless the apostasy comes first, and the man of lawlessness (the Antichrist) is revealed, the son of destruction, who opposes and exalts himself above every so-called god or object of worship, so that he takes his seat in the temple of God, displaying himself as being God". (2 Thes. 2: 3-4)The Day of the Lord is a time, I believe coming soon, when God will remove the spiritual blindness from the eyes of the Jewish nation, and they will call upon the name of the Lord. This Jesus, who lived on earth at an actual time in world history, who 40 days after He rose from the dead ascended into the clouds, will descend from the clouds at an actual time, returning to Jerusalem and defeating the armies of the world gathered against Him. At this time the unholy trinity; the evil one, the Antichrist and the False Prophet, will be bound and Jesus will rule on the earth, which will then be unaffected by the rebellious leadership of the evil one, for about a thousand years. At the end of the thousand years the evil one will be released, he will deceive once again the nations and gather them together to wage war against Jesus, the saints and the holy city of Jerusalem. This time God will bind and seal away the evil one for good, there will be a resurrection and a judgment of all mankind who did not have a reborn spirit, and then God will end the world as we know it, creating a new heavens and a new earth. Those whose names were written in the book of life will go into eternity with the Lord Jesus, and those whose names were not will suffer eternal separation from God and His people.
The Day of the Lord will be a time of great trouble in the entire earth, but expecially in Israel. There will be wars and earthquakes, giant hailstones and meteor impacts, demon armies and famine, and depending on how one calculates scripture, one quarter to three quarters of the world population will die within a seven year period. Death by martyrdom will be common for all who confess Jesus as Lord and Savior, and lawlessness will be everywhere.
The Thessalonians were going through a great period of persecution and hard economic times. They had been taught by Paul on one of his previous visits about the Day of the Lord, and evidently after Paul was gone they came under the impression from other sources that they were now in The Day of the Lord. Paul wrote to reassure them that The Day had not yet begun, and also that those in their community who had recently died had not missed out on being gathered to meet the Lord. "Now we request you brethern, with regard to the coming of our Lord Jesus Christ, and our gathering together to Him, that you not be so quickly shaken from your composure or be disturbed either by a spirit or a message or a letter as if from us, to the effect that the day of the Lord has begun". (2 Thes. 2: 1-2)
Paul goes on to say that the Day of the Lord will not come until "the apostasy" comes first, and the man of lawlessness, who is called elsewhere in scripture, "The Antichrist", is revealed. The word "apostasia" has been translated into English in our current bibles as "apostasy". The word has the sense of "falling away from" or "being removed from", and so the understanding we get from the word apostasy is that of a falling away from the faith. But English translations before the King James version rendered the translation as "the removal". This is interesting, because if that is the proper rendering of "apostasia" Paul is telling the Thessolianians that the Day of the Lord cannot begin until something is removed that is restraining the coming of the Antichrist, an idea consistant with verse 6; "And you know what restrains him now, so that in his time he may be revealed".
There are different opinions as to who or what that restrainer is. Some early church fathers believed it was human government, as represented by Rome. Roman law prevailed throughout the world known to those early theologians, and the might of Rome kept lawlessness in check. Others believve that it is the archangel Michael, who is holding back the spirit of the Antichrist until the proper time. And a third opinion is that presence of the Church, or the Body of Christ, being indwelt with the power of the Holy Spirit, is now restraining the worldwide lawlessness that will accompany the arrival of the Antichrist, a condition that must precede the return of the Lord. "And you know what restrains him now, so that in his time he may be revealed. For the mystery of lawlessness is already at work . . . that is, the one whose coming is in accord with the activity of Satan, with all power and signs and false wonders, and with all the deception of wickedness for those who perish". (2 Thes. 2: 6-9)
I believe the third one was what Paul was telling the Thessalonians. The Church (which includes them) must be removed before the revealing of the Antichrist and with it the worldwide rebellion against God that he would help bring. God had been patient with rebellion and lawlessness, but He would not let it go on forever. Just as the evil one was allowed to deceive one third of the angels to follow after him, so would the evil one, with the help of the Antichrist and the False Prophet, be allowed to deceive the nations so that truth could finally conquer falsehood, and light could finally roll back the darkness. The Holy Spirit will be present in the hearts of those who become reborn after the removal, but the intercesion of believers will not hold back the culmination of rebellion that God will now allow. Because of rebellion the world and all who lived in it had been subject to fear, corruption, pain and death. But Jesus was going to return as Redeemer King, and all rebellion would be dealt with. Although the condition of the Thessalonians was harsh, the world wide condition of lawlessness, as led by the Antichrist, could not begin until they are removed. And they can know that God's promise for their removal, as well as for the resurrection of their loved ones, was still valid because the Antichrist would exalt himself above every so-called god, and place himself in the Jewish temple to be worshipped, and that obviously had not yet happened.
All the English translations prior to the King James rendered the word apostasia as "the removal". This was not done by the translators to further a "rapture" theology, since at that time the early reformers still favored Roman Catholic doctrine on the interpretation of what would happen in the last days and what was the timing of the return of Jesus. Fourth century Catholic theologians had a world view that did not include the rebirth of Israel or the regathering of the Jewish people into that land, or a physical return of Jesus as the longed after Jewish Messiah, finally accepted by them, who would rule the Gentile nations from Jerusalem for 1000 years. The book of Revelation was spiritulized, as were prophecies in Daniel, Ezekiel and elsewhere to reflect that theology. Catholics do teach that in the last days there will be an apostasy, or falling away from the Roman Catholic faith, with a coming of an Antichrist, who may even be a false pope. But God will protect the true "institutional" Church during that time, until the Antichrist is once more bound by Michael.
Caholic theology views it's institutional Church as replacing Judaism. Theirs is the new priesthood, and Jesus is already present on the earth through His presence in the sacraments, especially communion and the display of the host. Through His establishment during His time on earth of the sacraments and the apostolic based priesthood, He will not need to return until the final judgment, just prior to the new heavens and the new earth. Although most Protestants have a historical rejection of the pope, the priesthood, and the sacramental system, they have still retained a theology that transfers God's unrevokable promises for the Jewish people and nation upon the Church, although they define Church differently. The majority of Protestant denominations still spiritualize many parts of scripture, including most or all of the prophetic passages.
The Catholic Church explicitly rejects the idea that Jesus will return to earth to rule for 1000 years. Point 676 in the Catechism Of The Catholic Church states; "The Church has rejected even modified forms of this falsification of the kingdom to come under the name of millenarianism, especially the intrinsically perverse political form of secular messianism". (It is "intrinsically perverse" because the return of Jesus to rule on the earth would upset the need for apolstolic succession, sacraments, etc.) Catholic theology accepts a tribulation period, which is defined as a period of apostasy from Catholicism, perhaps accompanied by other worldwide diaster, and led by an Antichrist. That period will end when the Antichrist is bound by the archangel Michael. This will usher in a universal Time of Peace, when the nations will flock to the presence of Christ as found in the sacraments and the priesthood of the Catholic Church. At the end of that undetermined time Michael will release the Antichrist, who will gather the nations against the Chruch, which is ruling from Jerusalem at this time, for the final war of Gog and Magog. It is at this time that the Church will be caught up to meet Jesus in the air. The Bride will then immediately return with Jesus to do away with all rebellion. There will be a final judgment, and finally "a cosmic upheaval of the passing world".
I believe that there is coming a specific point in time when everyone who has a reborn spirit will be physically removed from the earth to meet the Lord in the clouds, and thus to reside with Him in His Kingdom forever. This will be proceeded by a resurrection of the physical bodies of all those from the time of Jesus until now who had a reborn spirit at the time of their death. There will be left many people in the Protestant, Catholic and Orthodox Churchs, as well as many Jews, alive at that point in time who did not have a reborn spirit, which comes about through faith and not through baptism, or obedience to the tenants of any particular faith tradition. The day after the removal all of these chruches will be filled, and there will quickly arise false teachers and prophets, some even accompanied by false signs and wonders, who will deny the truth and confuse those who honestly desire to turn to God. There will be signs in the heavens to deceive the world. I believe one will be the appearance of the Virgin Mary, appearing clothed with the sun, standing on the moon, with twelve stars around her head as a crown. This description comes from Revelation 12, a woman Joseph saw in a dream which scripture interprets as the Jewish nation, but which has been intrepretated by the Catholic Church as Mary. This apparation will say that her womb which bore Jesus is the new ark of the covenant, and that during these times they should find their safety in her. There will be many other signs as well, leading away from surrender to Jesus, and ultimately toward the worship of the evil one, who will sit in the rebuilt temple in Jerusalem, proclaiming himself to be god.
But scripture also shows that God will have many ways during this awful time to proclaim the eternal gospel throughout the whole world. Many who receive that good news will be killed, choosing light and truth over darkness and lies. Paul told the Thessalonians that, although they too might have to die for their faith, they could not now be in that time of lawlessness and judgment.
"But we should always give thanks to God for you, brethren beloved by the Lord, because God has chosen you from the beginning for salvation through santification, by the Spirit and faith in the truth". (2 Thes. 2: 13)
"Now may our Lord Jesus Christ Himself and God our Father, who has loved us and given us eternal comfort and good hope by grace, comfort and strengthen your hearts in every good work and word". (2 Thes. 2: 16-17)