That's true, in part. The earliest 'books' included in the NT were written roughly 40 years after the death of Jesus by Paul, a man who never met Jesus, roughly in the late 60s AD. The others followed (in time) his epistles (letters) to the churches he founded, with the "Book of John" and "Acts", believed to have been written by the same man, roughly 40 years after Paul's first letter. And unless the disciple John lived to be roughly 120 years old, he didn't write the books attributed to him. It was common and accepted at that time for a writing to be attributed to a name that is well known in order for it to get any attention. Even all of the letters attributed to Paul aren't believed to have been written by him.