Folks who teach a pre tribulation gathering of the church do not take into account that before Paul(who they say taught a pre-trib gathering) there was a thriving church with thousands of members who were being taught that Christ would return at some future date, in the sky, with trumpet blast, and angels, after the tribulation, and gather the believers to Himself in the sky. How do I know that? Because Jesus taught His return and the gathering of the believers, to the apostles, and instructed the apostles to teach it to the church. The church from day one was waiting for the return of Christ to gather them, and the only return of Christ that the church had been given was the post tribulation return of Christ. Think for a moment, the first church before Paul had to be post tribulation gathering(because there was no other teaching). So before Paul we have the church believing in the return of Christ that Jesus had given the apostles to give to the church, a post tribulation gathering. So years later when Paul joined the church he would have had to have accepted the post-tribulation gathering just as the rest of the church was believing. This is shown because Paul described the return of Christ in the same way that Jesus did. This proves that the Thess letters describe a post-tribulation gathering and not a pre tribulation gathering as has been supposed...so no pre tribulation gathering of the church.
matthew 24:29-31 "Immediately AFTER the tribulation of those days shall the sun be darkened, and the moon shall not give her light, and the stars shall fall from heaven, and the powers of the heavens shall be shaken: 30And then shall appear the sign of the Son of man in heaven: and then shall all the tribes of the earth mourn, and they shall see the Son of man coming in the clouds of heaven with power and great glory. 31And he shall send his angels with a great sound of a trumpet, and they shall gather together his elect from the four winds, from one end of heaven to the other."