1 Thessalonians 4:17

Then we which are alive and remain shall be caught up together with them in the clouds, to meet the Lord in the air: and so shall we ever be with the Lord.

We which are alive and remain shall be caught up - after having been "changed in a moment" (1 Corinthians 15:51-46). Again he says "we," recommending the expression to Christians of all ages, each generation bequeathing to the succeeding one a continually increasing obligation to look for the coming of the Lord (Edmunds). If Christ's servants be secretly caught up (as some think) before the judgments upon the earth, how shall the Gospel be preached up to the end? (Matthew 24:14) Also, the gathering of the elect succeeds the great tribulation through which, though shortened for their sakes (Matthew 24:21; Matthew 24:29), they have to pass: but the elect there are probably Jews: the vintage of judgments on apostate Christendom succeeds the harvest of the righteous (Isaiah 26:20; Isaiah 61:2; Daniel 12:1; Zephaniah 2:3; Malachi 4:1; Revelation 11:7; Revelation 11:11; Revelation 14:15; Revelation 14:18: see note, Jude 1:14).

Together with them - all together: the raised dead and changed living forming one joint body.

In the clouds - Greek, 'in clouds.' The same honour awaits them as their Lord. He was taken in a cloud at His ascension (Acts 1:9), so at His return with clouds (Revelation 1:7) they shall be caught up in clouds, as His and their triumphal chariot (Psalms 104:3; Daniel 7:13). Ellicott explains, 'robed round by upbearing clouds' ('Aids to Faith').

In the air, [ eis (G1519) aera (G109)] - 'into the air:' caught up into the region just above the earth, where shall be the meeting (cf. Matthew 25:1; Matthew 25:6) between them ascending and their Lord descending. Not that the air is to be their lasting abode with Him. When a king enters his city the loyal go forth to meet him, the criminals in confinement await their judge (Chrysostom).

And so shall we ever be with, [ sun (G4862): not merely in company with, meta (G3326), but in coherence with (Ellicott)]

The Lord. No more parting, no more going out (Revelation 3:12). His point being established, that the dead in Christ shall have equal advantage with those found alive at Christ's coming, he leaves undefined the other events foretold elsewhere (as not necessary to his discussion) - Christ's reign on earth with His saints (1 Corinthians 6:2), the final judgment, and their glorification in the new heaven and earth.