Here is absolute proof from the Bible that the Rapture happens AT Christ’s second coming, and not before.

‘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.’
(1 Thess. 4:15)

Let’s break this down . . .

‘we which are alive and remain UNTO THE COMING OF THE LORD’

We who are still alive at the Lord’s second coming . . .

‘shall not prevent them which are asleep’

Shall not ‘prevent’ (go before) them which are ‘asleep’ (dead).

The Christians who are alive, going up (Rapture), will not take place before / until the dead are resurrected.

And yes, this verse IS talking about the Rapture. Here are the next verses, to prove it:

‘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:’ [‘Rapture’] ‘and so shall we ever be with the Lord.’ (1 Thess. 4:16-17)

This passage describes the SECOND coming of the Lord.  There IS NO ‘third coming’!