The sudden "depature" or rapture or 'snaching away" of Christians in not a new teaching. The rapture is taught in the NT and was believed by early Christians:
Ephraim The Syrian
Ephraim (306 AD – 373 AD) was made a deacon in the church in Syria in 338 and later became the bishop of Nisibis. Although he was made a “saint” in the Roman Catholic Church, he was not involved in Catholicism and did not even live in the Roman Empire until the final years of his life. The book Pseudo Ephraim was one of his still existing works. It was called “Pseudo” because of later dispute over authorship. However the book’s one reference to the rapture is very compelling:
In his work, On The Last Times 2, he wrote:
“Why therefore do we not reject every care of earthly actions and prepare ourselves for the meeting of the Lord Christ, so that he may draw us from the confusion, which overwhelms all the world? .....
Or do you not believe unless you see with your eyes? See to it that this sentence be not fulfilled among you of the prophet who declares: “Woe to those who desire to see the day of the Lord!” For all the saints and elect of God are gathered, prior to the tribulation that is to come, and are taken to the Lord lest they see the confusion that is to overwhelm the world because of our sins.
Cyprian
Cyprian (200 AD – 258 AD) – Cyprian was Bishop of the church in Carthage. During his short stint as leader of the church, he guided the flock through intense persecution at the hands of the Roman Empire. In 258 AD after spending seven months of confinement to his home by order of Roman authorities, he was beheaded for his faith. Several of his works still exist today.
In Treatises of Cyprian he wrote in describing the end times Great Tribulation:
“We who see that terrible things have begun, and know that still more terrible things are imminent, may regard it as the greatest advantage to depart from it as quickly as possible. Do you not give God thanks, do you not congratulate yourself, that by an early departure you are taken away, and delivered from the shipwrecks and disasters that are imminent? Let us greet the day which assigns each of us to his own home, which snatches us hence, and sets us free from the snares of the world and restores us to paradise and the kingdom.”