Now may the God of peace Himself sanctify you entirely; and may your spirit and soul and body be preserved complete, without blame at the coming of our Lord Jesus Christ. [1 Thessalonians 5:23]
A reminder from Paul that Christ will come again. When He comes again, the dead in Christ would rise to the sky, and those in Christ who are still alive will also be caught up in the sky to meet Him. It is an appointment in the sky with Christ. We do not know when that day is but it will come. The more important question we should ask ourselves is whether we would be found blameless on that day.