Most Bible believing Christians understand that 1 Corinthians 15:51-57 and 1 Thessalonians 4:13-18 teach that Jesus will remove the Church sometime before He destroys His enemies at the battle of Armegeddon. Those who believe in this event often refer to it as the Rapture (the Latin word for "to be caught up"). They all generally agree that the Rapture will occur in some connection to the Tribulation also known as the Time of Jacob's Trouble and Daniel's Seventieth Week. Those who hold the view that this event will occur at the end of the Tribulation, known as the Post-tribulation Rapture View, base their view on the idea of "meeting the Lord in the air" as He returns. This would immediately require a U-turn, as Christ is descending to begin His Millennial Kingdom. It also would allow no time for the Judgment Seat of Christ, or the Marriage of the Lamb to His bride (the Church), both of which occur in heaven prior to His Second Coming.
Another interpretation is known as the Mid-tribulation Rapture View. It results from misunderstanding two areas of Scripture. One area is that only those Christians who are good enough, or who are seen as being faithful at the moment Christ returns, will be removed. Who is ever good enough? Since the middle of the Tribulation begins the Great Tribulation or the Wrath of God, and the Church is not appointed to wrath (1 Thessalonians 1:9-10; 5:9), God will remove us at that time. Also, Jesus told His disciples that they would face tribulation (John 16:33). But, there are two reasons He did not refer to the seven year period known as the Tribulation: the disciples are already dead, and the Church has always suffered tribulation.
The other area of misunderstanding has to do with "the last trump" in 1 Corinthians 15:52. This trump is the last that the Church will hear on earth as it is being called up to heaven. The last, or seventh trump of Revelation 11:15 is in the middle of the Tribulation, and is part of God's judgment on Israel. It is absolutely essential that one views the Church and Israel as two separate entities. Remember, the Tribulation is the judgment ending the fifth dispensation, and the Church, or the sixth dispensation is a parenthetical period within the fifth. All seven trumps in Revelation sound during the Tribulation.
Perhaps the best reason for believing that the Rapture of the Church occurs before the tribulation (Pre-tribulation Rapture View) is that both Jesus and Paul teach that the Church should not worry about His coming for us. In parallel teachings (John 14:1-3 and 1 Thessalonians 4:13-18), they tell the Church "Let not your heart be troubled" and "Comfort one another with these words." Take the time to compare these two passages and marvel in their similarities. Christ's return is the hope of the Church, and seen as His glorious appearing (1 John 3:2-3 and Titus 2:13). Those expecting the Church to go through any or all of the Tribulation certainly have a dim view of their future. One could hardly comfort others with that view. So keep looking up; your Redemption draweth neigh!