The Rapture is an event that will take place sometime in the near future. Jesus will come in the air, catch up the Church from the earth, and then return to heaven with the Church. The Apostle Paul gave a clear description of the rapture event in his letters to the Thessalonians and Corinthians.
"For the Lord himself shall descend from heaven with a shout, with the voice of the archangel, and with the trump of God: and the dead in Christ shall rise first: Then we which are alive and remain shall be caught up together with them in the clouds, to meet the Lord in the air: and so shall we ever be with the Lord. Wherefore comfort one another with these words." (1 Thess, 4:16-18).
"Behold, I show you a mystery; We shall not all sleep, but we shall all be changed. In a moment, in the twinkling of an eye, at the last trump: for the trumpet shall sound, and the dead shall be raised incorruptible, and we shall be changed. For this corruptible must put on in-corruption, and this mortal [must] put on immortality" (1 Cor. 15:51-53).
