The Rapture is referred to as the first phase or stage of the second coming of Christ, it is the taking away of all living saints and all who died in the Lord. It is the catching away of all true believers in Christ, to meet the Lord in the air at the sound of the trumpet.
The Rapture will take place before the Great Tribulation and can happen any time from now. In the twinkling of an eye” without a moment warning, the trumpet shall sound and the dead in Christ shall rise first; then we which are alive and remain shall be caught up together with them with the Lord” it is the first of the last day event.
51 Behold, I shew you a mystery; We shall not all sleep, but we shall all be changed,
52 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.
53 For this corruptible must put on incorruption, and this mortal must put on immortality.
1Thess. 4:13-18, 5:4-9;
But I would not have you to be ignorant, brethren, concerning them which are asleep, that ye sorrow not, even as others which have no hope. 14 For if we believe that Jesus died and rose again, even so them also which sleep in Jesus will God bring with him.
15 For this we say unto you by the word of the Lord, that we which are alive and remain unto the coming of the Lord shall not prevent them which are asleep. 16 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: 17 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. 18 Wherefore comfort one another with these words.
But ye, brethren, are not in darkness, that that day should overtake you as a thief. 5 Ye are all the children of light, and the children of the day: we are not of the night, nor of darkness. 6 Therefore let us not sleep, as do others; but let us watch and be sober.
7 For they that sleep sleep in the night; and they that be drunken are drunken in the night. 8 But let us, who are of the day, be sober, putting on the breastplate of faith and love; and for an helmet, the hope of salvation. 9 For God hath not appointed us to wrath, but to obtain salvation by our Lord Jesus Christ,
Remember ye not, that, when I was yet with you, I told you these things?
2:6 And now ye know what withholdeth that he might be revealed in his time.
2:7 For the mystery of iniquity doth already work: only he who now letteth will let, until he be taken out of the way.
If by any means I might attain unto the resurrection of the dead.
20 For our conversation is in heaven; from whence also we look for the Saviour, the Lord Jesus Christ:
21 Who shall change our vile body, that it may be fashioned like unto his glorious body, according to the working whereby he is able even to subdue all things unto himself.
3 Behold, what manner of love the Father hath bestowed upon us, that we should be called the sons of God: therefore the world knoweth us not, because it knew him not.
2 Beloved, now are we the sons of God, and it doth not yet appear what we shall be: but we know that, when he shall appear, we shall be like him; for we shall see him as he is.
3 And every man that hath this hope in him purifieth himself, even as he is pure.
My beloved Brethren be ye stedfast, unmoveable, always abounding in the work of the Lord, forasmuch as ye know that your labour is not in vain in the Lord.