Who wrote a text is a different question from whether or not the text was copied accurately. Before the printing press, scribal errors could accumulate over ti

Who wrote a text is a different question from whether or not the text was copied accurately. Before the printing press, scribal errors could accumulate over time. It was a fact of life for every religious group that their own copy of a sacred text had at least a few scribal mistakes, and methods were developed to identify and correct errors. I cannot comment on Christian or Muslim approaches, but among Jews it took centuries to develop a sufficiently reliable system of detecting and correcting scribal errors to give us an acceptable copy of the Hebrew bible (the Masoretic text). One of the reasons the Dead Sea Scrolls was such an important discovery is that the Hebrew texts discovered there are extremely close to the Masoretic text, which confirmed its reliability.