The effect of this verse is to reinforce Paul’s message that no Christians, neither the dead, nor those who are still alive, will be separated from Christ at the time of his coming. We who are living at that time (literally “we [emphatic], the living, the left-behind,” exactly as in verse 15) will be with them, that is with the Christians who have died; and all Christians will from then on be always with the Lord—a statement which contrasts strikingly with the various kinds of figurative language which have gone before.
The words translated along with most commonly mean “at the same time as” (cf. Zürcher Bibel Luther 1984). This conflicts slightly with the preceding first and then, but in a passage using so many figures of speech, this is not a serious problem. Consistency in the use of figurative language is not one of Paul’s strong points anyway (cf. e.g. Romans 11.16-24). The words translated along with (see also 5.10) may, however, also mean “in the same place as,” and this may be the most natural basis for translation here, for example, “we will all be gathered up to be with them, and to meet the Lord in the air.”
We … will be gathered up includes the idea of being violently caught or snatched away (that is, from earth; cf. Acts 8.39). There are two problems involved in translating we … will be gathered up along with them. First the passive expression may be difficult, since an agent is implied, and in some languages it may need to be expressed. The obvious agent in this context is God, so one may translate “God will gather us up together.” Second, the implication of meeting Jesus in the air may suggest a term for “gathering” which would mean “lift up together” or “snatch up.” Such a term, however, could imply violence, as when the police or soldiers seize a thief. In some translations, therefore, a causative expression is used: “God will cause us to come together.”
It would be wrong to translate in the clouds in such a literal way as to suggest that the Christians will be “hidden from sight.” The apparent meaning here is “up where the clouds are.” This coincides with the meaning suggested by the phrase in the air, rendered in many languages simply as “in the sky.”
The word translated meet is an unusual one. In secular Greek, it is used in referring to ceremonies held on the occasion of a state visit, and specially to the inauguration of a ruler or important official. But the idea of going out to meet God is also found in the Old Testament (e.g. Exodus 19.10-18). The general idea is that of a solemn, not a casual or accidental, meeting. For some languages the appropriate connotations of a word translating meet may be contained in a term suggesting “to greet the Lord in the sky,” or “to gather round the Lord in the sky.”
There is a difference, both in the Greek words and in their meanings, between so in this verse and so then in the verse 18. The term translated so summarizes what has gone before, while the word translated so then indicates a relation of means and result. The context shows very clearly that we here includes all Christians.
We will always be with the Lord is in some languages best expressed as “we will always remain with the Lord,” or “… continue with the Lord.” In some instances this may be rendered “we will always stay where the Lord is,” or even “we will always accompany the Lord.”
Quoted with permission from Ellingworth, Paul and Nida, Eugene A. A Handbook on Paul’s First Letter to the Thessalonians. (UBS Handbook Series). New York: UBS, 1976. For this and other handbooks for translators see here .