They checked and rechecked their work, to make sure it perfectly matched.
What the New Testament writers originally wrote is preserved better than any other ancient manuscript.
The accuracy of today’s Old Testament was confirmed in 1947 when archaeologists found “The Dead Sea Scrolls” along today's West Bank in Israel.
"The Dead Sea Scrolls" contained Old Testament scripture dating 1,000 years older than any manuscripts we had.
That would probably be true if the translations were being made from other translations.
But translations are actually made directly from original Greek, Hebrew and Aramaic source texts based on thousands of ancient manuscripts.
The other two books were written by Mark and Luke, close associates of the apostles.