Timing of Second Advent
Throughout the centuries, many have declared that the end of the world is at hand. Sometimes, they mean by the hand of man in nuclear holocaust or some disease outbreak. Sometimes they mean at the had of God. If it's any consolation, at least the entire world won't be destroyed by nuclear weapons, as it would be real hard to fulfill the rest of the prophecies of the Bible if we are all dead already. That isn't to say there won't be any nuclear destruction in the world's future. Just that it won't be a world wide calamity.
In 2 Thessalonians 2:1-5, Paul continues his thoughts about the coming of Jesus (both the rapture and the second advent) from chapter 1. Here, since Paul is talking about the Christians being gathered up to Christ, he is speaking of the rapture of the church. He warns the readers to not pay any attention to any rumors that the rapture and second coming are near at hand or already passed. They should disregard all such nonsense, even if the letter purports to come from Paul. All we can say, even today, is that the last prophecy that had to be completed before the rapture and second coming could occur has been fulfilled. But it may be millennia before the actual end occurs. Or it could happen before this is posted (if you're reading this, it didn't).
Speculation about the timing of the rapture is pointless. I suspect that is one reason why the timing of Christ's birth can only be speculated upon. While I'm sure it wasn't December 25th (being on the Jewish calendar it would move like the time of His death: Passover), and I lean toward a fall festival like the Feast of Tabernacles as being a good time, I don't know. Likewise, we don't know when the rapture will happen. We may feel it will be soon, but we cannot know for certain. The timing of the second advent, however, is set in prophecy based on certain end time post rapture events. And the rapture of the church is something the world leaders won't be able to hide, although I'm sure they will try. They'll probably try to paint it like the wraith of Stargate Atlantis fame, I suspect - remember the craft swooping over and beaming everyone in their path up?
Here, Paul reminds the readers that before the second advent can happen, the anti Christ will need to be revealed and will set himself up to be worshiped in the temple (which also hasn't been rebuilt as of this writing, although much preparation work has been accomplished). Accompanying the rise of the anti Christ will be a great falling away in the faith. I think we can all safely say that there is a falling away which has been going on for a century or so. Whether or not it will get more extreme is anyone's guess.
Paul had told the Thessalonians these things, but they had evidently forgotten or had been led astray by false teachers or false documents. The warning to them is the same warning to us today. If you're in doubt about something, check out what the Bible says. Go back to older versions or literal versions to compare to make sure some modern translation hasn't changed the meaning of the verses. Like his readers, we need to remain steadfast in the truth the Bible declares and we need to ignore what we hear that isn't backed up by what the Bible says.
I'll grant that there are portions of prophecy that we probably won't understand until it happens, and then we'll all be going "Duh! Why didn't we see that!". There are elements of pre-history which everyone wishes God had put a few more words about. But the basics of the Bible are pretty black and white. If some religious leader is trying to paint sin as good, that leader is in the wrong, regardless of how well he or she is respected in their own denomination.
What is Taken Away
Paul then reflects on what must happen before the anti Christ is revealed in 2 Thessalonians 2:6-10. Many debate what is taken out of the way in order for the anti Christ to be revealed. Clearly, it won't be world government or authority, as these will continue throughout the reign of the anti Christ. It won't be laws, because there will still be laws in effect (for example the law that the anti Christ must be worshiped). The Holy Spirit is still at work trying to save people as there are martyrs for the faith during the tribulation. God's word won't be taken away because angels will proclaim the gospel message in every tongue and to every people during a period in the tribulation, accompanied with a warning to not take the mark of the beast. So what's left?
The only thing that makes any sens is that the church is removed. We are the only thing that holds back lawlessness that could disappear. Once the church is gone, the anti Christ will make himself known. Of course, Paul's words here also indicate that even with all of Satan's power in working signs and lying wonders that will try to deceive the world into turning away from Christ, the Lord is going to destroy him when He returns for the battle of Armageddon.
Those who rejected Christ before the rapture of the church, and those who refused to listen to the angel's spreading the word throughout the heavens will have given up the chance to be saved.
God's Opposition to Those who Refuse to Accept Jesus
2 Thessalonians 2:11-12 warns that God will not always strive with mankind. It is God's desire that everyone be saved (Romans 1:21-22). He doesn't choose to lose a single soul. However, He also provided each of us with a free will, and if we are resolute in our desire to forge our own path without Christ, the Holy Spirit will eventually quit dealing with our souls. This is the sense of the verse. The Holy Spirit will try to work against the sings and wonders of Satan talked about in verse 2:9, but those signs and wonders will be a strong delusion for those who wish to hate and reject God and believe a lie. Many will see what Satan is doing, and having never seen, read, or heard about the power of God, they will choose to believe a lie.
It is also clear that the lure of sin will be just as strong post-rapture as pre-rapture. The pleasure in unrighteous living is a real thing. In addition, with the exception of some memories of what the Christians have long pointed out was right and wrong, they'll only eventually have an angel reminding them of truth. The church won't be there pointing out sin. The anti Christ will be promoting sinful things, I presume. It will be easy for people to choose to enjoy sin without any perceived fear of penalty. And there will also be a huge amount of anger against God because of the destruction from both the rapture and the tribulation. Self-righteousness will still be a problem.
For those who knew the Bible and perhaps had some knowledge of what the rapture and tribulation period might look like, they will have a strong incentive to turn to God. But there will also be a lot of fear in spreading the fact that they are a Christian, because Christians are going to be blamed for the mess the world is now in. That, coupled with the eventual mark of the beast which will limit transactions, will make choosing God tough during the tribulation period.
Hold Fast
In 2 Thessalonians 2:13-17, Paul calls all Christians to stand fast and hold on to what they had learned, whether coming directly from him or via a letter from him. He hoped that all of them would be solidly established and desirous to do good works and spread the good word to everyone they knew, so that all would be saved.
His words are a challenge to us today as well. The church is continually being berated for being old school and not being with the times. There is a strong push to stop condemning some sins as such. Just let it be and you'll keep or get more members. Don't worry about what you preach or teach. Preach easy sermons that don't hurt people's feelers.
Paul would be aghast. He'd say the falling away he warned about started at the leadership of churches, and the letter he would write about it would be long, without many periods.
The reality is there is just one gospel. There is only one judge of right and wrong. He's laid out His directives throughout the Bible. There are many who don't like what He established. They don't understand His reasons. The just don't like Him very much. That's one result of free will.
But regardless of what we think about what the Bible says, God will judge justly at the appointed time. He won't check what the (insert random denomination here) believed when judging right and wrong. He may have strong words to say when judging our works. But in the end, it's His word and standards which will prevail.
Like Paul, we need to pray for all of the church to receive God's love, consolation, and grace. None of us are perfect. None of us have a perfect understanding of all that God is and says. But we can all pray that we don't lead anyone astray and that we stay true to Him. Hold fast to what the Bible declares as truth, no matter what the world thinks.