Paul says that he wants to give us hope by telling us what is going to happen when Christ returns. And, not only to us who may still be alive, but to those who have died as true Christians.
This is important because this is part of the belief that we have to have, because Jesus died and rose again and was changed. We have to believe that the same thing is going to happen to us. We have already read that in Romans 8:29, where He has predestined us to be conformed to the image of His Son. And that means all the way.
So, let us read this with that belief, that faith, that hope.
So, not only is the idea there that Jesus died and rose from the dead, it is also well-known and believed that we will also rise in the resurrection just as He rose in His resurrection. What we see here is an unmistakable connection between Christ's resurrection and the hope of our salvation and resurrection to eternal life at His second coming. It is very clear, and it is said in very few words.
Those who die - a converted man or woman - will be brought with Jesus Christ at His return.