[Tennessee Nana]

“Much of the NT wa written after the last book of the assembled books was written.”

NOOOOOOOOOOOOOOOOOOOO

Much of the New Testament was written by Paul, and were letters to the Christians in the churches he had founded...

Several of the letters were written from prison, or during his journeys...

John, the beloved disciple of Jesus, was just a young man when Jesus was crucified and rose again, a finished work of redemption for us....

Paul was long dead when John, now an old man, wrote the Book of Revelation...

[broncobilly]

That is a detail that is up for debate, but is beside the point.
The Book of Revelation when it was written was just the Book of Revelation. That was the book that was not to be changed or added to. The NT was not assembled and the order of writings determined until many years after the Book of Revelation was written.

[maine-iac7]

Paul was long dead when John, now an old man, wrote the Book of Revelation...

Ahh - John the Beloved and John the Revelator were two different people