Answer
I think when we come to the text of Scripture, we have to let Scripture speak for itself. It claims to be inspired. We have enough evidence that it is truthful, therefore what the Scripture says I think we need to accept. When we come to the Pentateuch, it seems to me that it's clear that Moses is the one receiving the revelation from God and he's often told to write it down. And when we look at the structure of the book of Genesis, in the toledot, "these are the generations of," it appears that a single author, human author, has written this book, and that single author is Moses. When we take a look at the historical books, both pre-exilic and post-exilic, we take a look at Samuel and Kings and Ezra, Nehemiah and Chronicles, all of those reference back to material of the Pentateuch and claim it to be in the Law of Moses. And when we come to the New Testament, all four gospels, in fact, dealing with material from the Pentateuch, claim it to be from Moses, often in the very words of our Lord Jesus Christ himself. So, it seems that internally and externally we have evidence for a single author, that author being Moses, and writing empowered by the Spirit of God.
Answer by Dr. Stephen J. Bramer
Dr. Stephen Bramer is Professor and Department Chair of Bible Exposition at Dallas Theological Seminary