When will the Rapture take place?
The Rapture will take place when the last from among the Gentiles has been saved. This not only will, but must happen before the beginning of the Great Tribulation. Why? Because the Great Tribulation is the result of the Church's removal. The Great Tribulation cannot begin unless and until the Holy Spirit, who indwells the believer, has been removed.
A number of examples of this can be found in the Old Testament. Let's take a closer look at one. During Lot's time, the angels announced to him that Sodom and Gomorrah would be destroyed. Lot was urged to run for his life. During that episode, something significant was revealed; the hindering element for Sodom and Gomorrah's judgment was righteous Lot. The Bible says, "I cannot do anything until thou hast been removed hither." God could only implement judgment after the righteous one was removed. This corresponds with Scripture's statement that we, the Church, are not appointed to wrath.
But doesn't the Bible also say that we must enter the kingdom of God through much tribulation? That is true; however, the result of such tribulation is never condemnation but salvation. Peter wrote: "Wherein ye greatly rejoice, though now for a season, if need be, ye are in heaviness through manifold temptations: That the trial of your faith, being much more precious than of gold that perisheth, though it be tried with fire, might be found unto praise and honour and glory at the appearing of Jesus Christ"(1st Peter 1:6-7).