There is a basic rule in Catholic theological studies: If something sounds strange or a bit off in the New Testiment Scriptures, especially where Saint Paul is Conserned, Look to the Old Testiment and you can see from where he draws his ideas.

Saint Paul was a Highly Regarded Pharicee, a very learned man living the Jewish Faith Flawlessly. He studied under the greatest Rabi, Rabi Gamaliel of whom it is said in the Talmud

"Since Rabban Gamaliel the Elder died, there has been no more reverence for the law, and purity and piety died out at the same time"

Paul was the Greatest Student of the Greatest Rabi at the end of the 1st Century.

How is that relevant? It is relevant because the images that Paul draws from are the images that he is familiar with, those images of the teachings of the law and the prophets found in the Septuigent.

When Pual Qoutes from 1 Thesalonians 4:17, to get his context lets look at verses 15-18

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. For the Lord himself shall descend from heaven with a shout, with the voice of the archangel, and with the trump of God:and the dead in Christ shall rise first: Then we which are alive and remain shall be caught up together with them in the clouds, to meet the Lord in the air:and so shall we ever be with the Lord. Wherefore comfort one another with these words.

It is understood by Protestants that this is a bodily acention and that It is a "Secret Rapture" where pilots and bus drivers disappear leaving havoc in the "Secret Raptures" wake.

Let us now look at what Paul was really refering to. As he does elsewhere in Scripture, The well educated Jewish Rabi is refering to things that have happened in Old Testiment Scripture.

Exodus 19:16-19

And it came to pass on the third day in the morning, that there were thunders and lightnings, and a thick cloud upon the mount, and the voice of the trumpet exceeding loud; so that all the people that was in the camp trembled. And Moses brought forth the people out of the camp to meet with God; and they stood at the nether part of the mount. And mount Sinai was altogether on a smoke, because the Lord descended upon it in fire:and the smoke thereof ascended as the smoke of a furnace, and the whole mount quaked greatly. And when the voice of the trumpet sounded long, and waxed louder and louder, Moses spake, and God answered him by a voice

Note the similarities between the two passages.
Christ comes down/God comes Down There is Thunder and Lightning/Voices and Trumpets God is in a Cloud where he meats Moses/ Christ is coming down and meeting us in a cloud.

We also assend to Christ- Perhaps he will be on a mountain just like most every other time God Reveals himself to man.

An in depth and Honost study of these passages as well as others including Danial 7 where Christ assends to heaven and sits at the Right hand of the Father, In heaven not at an earthly mellenial Kingdom as Premelenialist suggest. In order for that to make sence Christ would have to decend to the New Earthly Jerusalem. The objections to the Very modern unbiblical fantasyn of a secret Rapture are endless.

It sure does sell books though.

The Catholic Church undrstands these passages as they were meant to be understood. In the same manor in which the rapture was presented to the Church by Paul. A one time event, a very loud event that is in no way secret.

The rapture, properly understood, is fully compatible with Roman Catholicism. The English word rapture comes from the Latin word raptus ("a carrying off"). This Latin word (or a similar one, rapio) is employed in the writings of Augustine and Thomas Aquinas, and it appears in the Bible, which indicates that the word rapture is perfectly legitimate in itself: we must simply be careful in how we understand its meaning.

What is the rapture, according to Roman Catholicism, then? It is simply the raising of believers, both alive and dead, into the clouds to meet Christ, as part of Christ's second coming. As Thomas Aquinas writes regarding Paul's teaching in 1 Thessalonians 4:

[The Apostle] is not speaking about the resurrection in terms of the order in which they shall rise, but of the order in which they will be taken up [raptum] to meet Christ. For when the Lord does come, first those who are found alive will die and then, immediately together with those who had died before, they will rise up and be taken up [rapientur] into the clouds to meet Christ, as Paul clearly says. (Commentary on 1 Thessalonians, 4.2)

On this Aquinas is following Augustine, who says that living Christians will "both die and rise again at once while caught up into the air" as part of the resurrection:

And why should it seem to us incredible that that multitude of bodies should be, as it were, sown in the air, and should in the air forthwith revive immortal and incorruptible, when we believe, on the testimony of the same apostle, that the resurrection shall take place in the twinkling of an eye, and that the dust of bodies long dead shall return with incomprehensible facility and swiftness to those members that are now to live endlessly? [...] For that there shall be a bodily resurrection of the dead when Christ comes to judge quick and dead, we must believe if we would be Christians. (City of God, 20.20)

Other church fathers viewed this passage similarly. George Leo Haydock, a more recent Catholic theologian, writes in relation to 1 Thessalonians 4:15,

God's command will in a moment raise and bring all to judgment. (Commentary)

Summary

These quotations should make it absolutely clear that Roman Catholicism does not accept any concept of a rapture that is separate from the final resurrection and the final judgment. The idea of dispensational Protestants that there will be a "secret" disappearance of believers several years prior to these events is thus utterly rejected.

However, the Bible, the church fathers, and more recent Catholic theologians agree that believers will be "taken up"—raptured—when Christ returns. Roman Catholics shouldn't stop using this perfectly legitimate word simply because dispensational Protestants have given it a different meaning.