Jesus knew that death of our physical bodies was only a temporary state. The disciples didn't understand His reasoning. They said well, if he's asleep that should do him good. He probably needs the rest. They totally missed it. So later in the passage he says" OK, he's dead, but do not panic! I shall raise him up!

Great word today my friend, thanks!

Thanks Mary ~ Here is a good commentary on this verse.  Hope you like it.  His, T.

1 Corinthians 15:51-52

15:51-52. Paul had revealed the same truth to the Thessalonians (1 Thess 4:15-17). The Rapture of the church was a mystery (
mysterion
) in that it had not been known in the Old Testament but now was revealed. (Cf. other "mysteries" - now revealed truths - in Matt 13:11; Luke 8:10; Rom 11:25; 16:25; 1 Cor 4:1; Eph 1:9; 3:3-4,9; 5:32; Col 1:26-27; 2:2; 4:3; 2 Thess 2:7; 1 Tim 3:9,16; Rev 1:20; 10:7; 17:5.) The dead in Christ will first be raised, and then the living will be instantaneously transformed. The trumpet, as in the Old Testament, signaled the appearance of God (cf. Ex 19:16). It is the last blast for the church because this appearance shall never end (cf. 1 Cor 13:12). (There is no basis for posttribulationists equating this trumpet with the seventh trumpet in Rev 11:15-19. The trumpets in Rev. pertain to judgments during the Tribulation, whereas the trumpet in 1 Cor 15:52 is related to the church.)
(from Bible Knowledge Commentary/Old Testament Copyright © 1983, 2000 Cook Communications Ministries; Bible Knowledge Commentary/New Testament Copyright © 1983, 2000 Cook Communications Ministries. All rights reserved.)