As for the Rapture, the meaning of 1 Thes 4:15-17 is that at the return of Christ (v.15) and the General Resurrection of the Dead (v.16), those who survive the persecution of the Antichrist will have no advantage in being resurrected over those who died before His Coming [CCC 1001]. All will go to meet Him and be with Him forever (v.17; cf. Rev 20:17-21:27).

The Catechism provides us with a general order of events at the End [CCC 673-677]. Chronologically they are,

1. The full number of the Gentiles come into the Church

2. The "full inclusion of the Jews in the Messiah's salvation, in the wake of the full number of the Gentiles" (#2 will follow quickly on, in the wake of, #1)

3. A final trial of the Church "in the form of a religious deception offering men an apparent solution to their problems at the price of apostasy from the truth." The supreme deception is that of the Antichrist.

4. Christ's victory over this final unleashing of evil through a cosmic upheaval of this passing world and the Last Judgment.

As Cardinal Ratzinger recently pointed out (in the context of the message of Fatima), we are not at the end of the world. In fact, the Second Coming (understood as the physical return of Christ) cannot occur until the full number of the Gentiles are converted, followed by "all Israel." 

Approved Catholic mystics (Venerables, Blessed and Saints, approved apparitions) throw considerable light on this order, by prophesying a minor apostasy and tribulation toward the end of the world, after which will occur the reunion of Christians. Only later will the entire world fall away from Christ (the great apostasy) and the personal Antichrist arise and the Tribulation of the End occur.

Although this is not Catholic doctrine, arising as it does from private revelation, it conforms to what is occurring in our time, especially in light of Our Lady of Fatima’s promise of an "Era of Peace." This "Triumph of the Immaculate Heart" (other saints have spoken of a social reign of Jesus Christ when Jesus will reign in the hearts of men) would seem to occur prior to the rise of the Antichrist. The optimism of the Pope for the "New Evangelization" and a "Civilization of Love" in the Third Millennium of Christianity fits here, as well. This would place us, therefore, in the period just before the events spoken of in the Catechism, that is, on the verge of the evangelization of the entire world. Other interpretations are possible, but none seem to fit the facts as well, especially when approved mystics are studied, instead of merely alleged ones.