True. The word “rapture” isn’t in Scripture. But that doesn’t necessarily mean it’s wrong to use the word as a descriptive term. Preachers and commentators use words that aren’t in scripture all the time, to “give the sense” (Neh. 8:8) to actual Scripture. As long as the commentary is backed up by actual Scripture, and causes the hearer to see the truth of Scripture, it is a good thing.
What the word “rapture” (violently seized, transported - Webster) is attempting to describe is what Scripture speaks of in 1 Thessalonians 4:16,17:
"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."
(KJV)
This is the resurrection of the body of Christ (1 Cor. 12:27), and the “mystery” of 1 Corinthians 15:
**“Behold, I shew 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 incorruption, and this mortal must put on immortality. So when this corruptible shall have put on incorruption, and this mortal shall have put on immortality, then shall be brought to pass the saying that is written, Death is swallowed up in victory.” ** (1 Cor 15:51-54) (KJV)
If none of this is going to happen then there is no point at all to Christianity because:
"But if there be no resurrection of the dead, then is Christ not risen:
And if Christ be not risen, then is our preaching vain, and your faith is also vain.
(1 Cor 15:13)(KJV)
Everything in Christian doctrine centers around this event commonly referred to as the “rapture.” If this word bothers you, then you can call it the “catching up,” etc., but don’t say the event isn’t in Scripture because it most certainly is; it is, in fact, the “blessed hope” of the body of Christ (Titus 2:13).
If you consider all this to be so much nonsense, this is probably because you aren’t saved, i.e., you’ve never trusted Christ as your saviour.