Paul had comforted the Thessalonian believers with the hope of the rapture in his first letter. Because of the intensity of persecution, though, confusion had set in. These suffering believers were afraid that the awful day of the Lord had come upon them. When Paul learned that his teaching (5:4) had been misinterpreted, he wrote a second letter for clarification. In order to assure them they were not experiencing the day of the Lord, he extended a guarantee to them: that day cannot come “unless the departure comes first, and the man of sin is revealed” (2:3). The interpretation of Paul’s promise depends on the meaning of the word ajpostasiva. This noun is compounded from ajpov, “away from,” and stavsi", “position, stance”, from i{sthmi, “stand.” Literally, the act of positioning oneself away is a departure or separation. That’s how we have rendered it. In secular Greek, this noun was used to refer to separatist political groups. From this sense, LXX employed it to denote “rebellion,” especially against God. Since James was familiar with the Greek Old Testament (he cites it in Acts 15:16-18 and Jam 2:23 and 4:6), it is probable that LXX usage underlies his phrase ajpostasiva from Moses” in Acts 21:21. However, his very phrase would be redundant if the concept of religious apostasy were inherent within the noun, for then he would not have defined the ajpostasiva as “from Moses.” From what other than Moses’ law could the Jew apostasize? While ajpostasiva was used in patristic sources in the technical sense of “apostasy,” the addition by James of the qualifying modifier suggests that in the New Testament, ajpostasiva does not carry that sense by itself.
Further, since the Thessalonians were recent converts from paganism, the relevance of LXX usage in Paul’s epistle to them is questionable. These believers would be more familiar with the noun’s Greek heritage. Liddell & Scott (1881:203) classify ajpostasiva as a “worse [later] form of ajpostavsi",” and give as one definition “distance.” Moulton and Milligan (1930:68) consider ajpostasiva “equivalent to ajpostavsi",” a noun commonly used in the sense of “departure.” Further, while the cognate verb ajfivsthmi sometimes describes a departure from godliness, it is often just the opposite:
In Acts 19:9, Paul departs from the unbelieving Jews.
In 1 Timothy 6:5, Paul instructs Timothy to depart from those who pervert the truth.
In 2 Timothy 2:19, those who name Christ’s name are to depart from iniquity.
Our understanding of ajpostasiva is supported by the syntax. The noun in this case has the definite article: “the departure.” The article cannot be generic; it must be anaphoric.[30] To what specific departure did Paul refer in Thessalonians? Had he discussed previously with them a specific time of apostasy? We see nothing of the sort in 1 Thessalonians. In contrast, the departure of the church is pre-eminent in the first epistle. Paul refers to this event and to our subsequent joy in Christ’s presence in 1:10, 2:19, 3:12 and 5:9,10, discussing it at length in 4:13-18. Within the immediate context of our noun, he writes of our gathering together with Christ (2 Th 2:1). We infer that Paul is referring back to a subject in which he has assiduously instructed his readers: “the coming of our Lord Jesus Christ and our gathering together to Him.”
Our interpretation of ajpostasiva as “departure” better serves Paul’s purpose in writing this chapter. Those who interpret ajpostasiva as “apostasy” assume that Paul refers to this “apostasy” as a sign to warn the Thessalonians of Christ’s return. However, Paul’s purpose is not to warn them of His impending return, but to reassure them in their persecution that they need not worry about enduring the wrath of God. It is not they who will be left behind. The unbelievers who refused the truth will be left behind (2:11-12).
Ironically, the chief text cited on behalf of the post-tribulation position occurs in the immediately preceding context. “It is just with God to repay affliction to those who afflict you, and to you who are afflicted relief with us, at the unveiling of the Lord Jesus” (1:7). All agree that this context describes our Lord’s return after the tribulation. However, we must not assume that the saints’ relief and the afflictors’ recompense are simultaneous. The nouns relief and affliction are not co-objects of the verb ajntapovdounai, “repay,” for in what sense is God’s relief a repayment of our afflictions? Afflicting the afflictors represents the Mosaic law of corresponding retribution, but our relief is not a corresponding reward – we all receive it, regardless of the degree of our faithfulness. The clause, “and [give] relief to you who are afflicted,” is a parenthesis, inserted in a manner almost characteristic of this passage: