Sorry but this is not quite right. Adherents of the rapture are numbered among Evangelicals and even mainstream Protestants, not just among the ‘fundamentalists’, who are a subset of Evangelicals and of Pentecostals. Moreover, very few adherents of the rapture doctrine would agree that only those who have received the ‘baptism of the Holy Spirit’ will be raptured: all saved persons will be raptured. To start with, all saved people receive the Holy Ghost when they receive Christ: the ‘in-filling’ of the Holy Ghost is a secondary blessing taught by only a minority of Pentecostals and Charismatic Protestants and Catholics. Not all who accept the Rapture teaching believe in the ‘in-filling’ of the Holy Ghost as a secondary blessing.
Moreover, there are and always will be both saved and unsaved persons even within actively-Christian churches and congregations. There are and will ever be people who have received the Gospel of salvation by grace through faith in Jesus Christ; and there are and ever will be members of churches and congregations who are trusting more in their own good works and merits than in the merits and finished work of Christ.
Most Evangelicals do NOT accept Roman Catholic notions of a ‘baptism by desire’ which might somehow grant salvation to some who are Buddhists, Muslims, or otherwise non-Christian. Evangelicals believe that one must receive Christ to be saved, and believe that all people receive the light of conscience and the light of Creation, by which they can be led to the Light of Christ. One who does not accepts the Light of Christ by becoming Christian can be assumed to have rejected to some degree the light of conscience and/or the light of Creation.
In any case, adherents of the Rapture doctrine would NOT say that Eastern Orthodox, Roman Catholic, or other Christians automatically have not received the Light of Christ (a synonym for ‘receiving the Gospel’ or for ‘receiving Christ’)–though there may be proportionally fewer who have received Him in those Churches because the EO and RCC do such a poor job of teaching the Gospel.
Palmas85 is correct that the contemporary Rapture teaching is a minority view, and a relatively recent one by the way. I do not subscribe to it myself. Roman Catholics do not believe in the popular Evangelical version of the Rapture. (Ultimately, all Christians believe in a ‘rapture’ at some point in Salvific history: the question is one of timing). As it is currently popularized, the Rapture teaching centers around the idea that God will remove His people from this Earth just prior to a time of tribulation and trouble, during which Satan will have free reign on the planet and will attempt to counterfeit Jesus Christ by raising up an Antichrist. The most notable event of occur during the time of tribulation will be the mass conversion of the Jewish people, and the attempt of Antichrist to annihilate them at the Battle of Armageddon. At the end of that time of tribulation (usually though not necessarily always believed to last 7 years) Christ will return with His Saints, rescue the Jewish people, destroy all of the wicked, and set up a Millennial Kingdom.
Most Christians do not believe that God will remove Christians from the Earth until the actual, visible Second Coming of Christ at the end of the World. There are various views about whether there will be a literal Antichrist, a literal time of tribulation, and a literal Millennium. It is generally agreed that during the time just before the return of Christ, Scripture teaches that Jewish people will convert to faith in Christ in unprecedented numbers. In general, eschatology–the study of ‘last things’, such as death and the End of the World–is an area of theology left wide open for much speculation. What one MUST believe as a Christian is that there is going to be a literal, visible return of Christ, a literal bodily resurrection of the dead in Christ, and a real and literal world-to-come.