1 Thessalonians 4:15
For this we say unto you by the word of the Lord, that we which are alive and remain unto the coming of the Lord shall not prevent them which are asleep. (1 Thessalonians 4:15)
By the word of the Lord.
 The apostle is appealing to a higher authority than his own (cf. on 1 Cor. 7:6, 10, 12, 25).
We which are alive and remain.
 Literally, “we the living ones, the remaining over ones,” that is, those who, in contrast with the righteous dead, remain alive until Christ’s return. Paul here appears to express a hope that he, and the converts to whom he is writing, will be alive when Jesus comes, a hope common with Christians of all ages. But he does not explicitly state that he will live until that great day (see Rom. 13:11; 1 Cor. 10:11; Phil. 4:5; Titus 2:13; see Additional Note on Rom. 13). He clarifies his thoughts on the matter in 1 Thess. 5:1-11, where he deals with the unexpectedness of the second advent and the uncertainty of his or their still being alive at the time of their Lord’s return (v. 10). It appears that the Thessalonian believers misunderstood Paul’s statements, and some willfully perverted them and taught that the day of the Lord was even then at hand (see on 2 Thess. 2:2). It was to rectify this error in their thinking that the apostle wrote his second letter a short time later (AA 264; see p. 262).
Coming.
 Gr. parousia (see on Matt. 24:3). Parousia was sometimes used for the arrival of a Roman general to celebrate a triumphal procession through the streets of a city. The word is thus appropriate for describing Christ’s triumphal return.
Not.
The negative is strongly expressed in the Greek.
Prevent.
 Gr. phthanō, “to come before,” “to precede.” This was the meaning of “prevent” when the KJV was translated. But the word has changed its meaning so that it no longer correctly translates the Gr. phthanō. Paul is assuring his readers that the living Christians will not be united with their Lord before those who have fallen asleep. “The dead in Christ shall rise first: then we which are alive and remain shall be caught up together with them” (vs. 16, 17). Thus the living saints will have no priority over those who have died in the Lord. This teaching makes clear the true state of those who have died “in Christ.” They are asleep, awaiting the Saviour’s coming. They have not yet been united with Him, but, like the living Christians, await the second advent for their longed-for union with the Master (cf. John 11:23-25). Neither class has precedence over the other; both will be taken to glory together by their Lord at His coming.