In this chapter of Thessalonians we find Paul addressing a basic aspect of life. He admonishes them on what to stay away from, and encourages them in the paths of living which lead to life. At the end of the chapter he plugs in a little glimpse of what the return of Jesus will be like. This is one of the passages often cited by the supporters of the rapture.
I do not want to get into a lot of detail in this forum, but the end of the chapter requires some understanding about the return of Jesus. The image Paul uses is the image of a king coming to a city. When the king is in the distance the people of the village would run out and greet the king celebrating as the king continued on to the city. This is the echo of the triumphal entry of Jesus in to Jerusalem just before the cross. The return of Jesus will happen in much the same fashion.
Note the people to greet the king, but they are not taken away from the city, they follow the king back to the city in great celebration. When Jesus returns it is not to take the Christians away to another place, rather it will be to return this world to the way things were before the Fall in Genesis. The place where people and God are in perfect relationship, and sin is absent. When the King returns to this place, we will greet Him and enter into the fullness of the created Kingdom.
In all reality the details do not really matter as much as the question of preparedness. Are you and I ready if that day is today? Are we living our lives in such a way that we would run to the king, celebrate and experience the fullness? The return of Jesus is not the question.