Rapture of the church in relation to the tribulation

In eschatology, it is important to remember that almost all Christians agree on these three things: 1) there is coming a time of great tribulation such as the world has never seen, 2) after the Tribulation, Christ will return to establish His kingdom on earth, and, 3) there will be a Rapture—a translation from mortality to immortality—for believers (John 14:1-3;1 Corinthians 15:51-52; 1 Thessalonians 4:16-17). The question is when does the Rapture occur in relation to the Tribulation and the Second Coming of Christ? Through the years three main theories have emerged concerning the timing of the Rapture: pre-tribulationism (the belief that the Rapture will occur before the Tribulation begins), mid-tribulationism (the belief that the Rapture will occur at the midpoint of the Tribulation), and post-tribulationism (the belief that the Rapture will occur at the end of the Tribulation).