What disturbed the Thessalonians was they thought Christ had already come, and that they’d missed it. Paul reassures them in the next verse, “Let no one deceive you by any means; for that Day will not come unless the falling away comes first, and the man of sin is revealed, the son of perdition” (2:3).
So, what was Paul’s primary theology about Christ’s return? We find it in two passages:
“Knowing the time, that now it is high time to awake out of sleep; for now our salvation is nearer than when we first believed. The night is far spent, the day is at hand” (Romans 13:11-12).
“Let your gentleness be known to all men. The Lord is at hand” (Philippians 4:5).
Paul is crying, “Wake up! It’s past midnight already. The Lord’s coming is drawing near, so stir yourself. Don’t be slothful. Jesus is coming for those who expect him.”
Skeptics may ask, “But what about Paul’s own words? He did say two things had to happen before Christ returns. First, the Lord can’t come until a great apostasy takes place. And second, the Antichrist has to rise up and proclaim himself God. We have to see the Antichrist sitting in the temple, demanding that people worship him, before Jesus will come.”
First of all, you have to be willfully blind not to see a raging apostasy gripping the whole world. Unbelief is seeping through nations, with believers falling away from faith on all sides. The apostasy Paul refers to has clearly arrived.
Secondly, according to John, the Antichrist is anyone who denies the Father and the Son. Moreover, he says, the increase of such Antichrists is proof we are living in the very last days. In short, nothing is holding back Christ’s return!