I believe that many things had been written before Moses. Adam, I assume, wrote the stories of the creation, the fall, the promise of the seed of the woman, etc., likewise the other fathers, especially Noah, wrote what happened at their time. Afterward Moses took this material and brought it into good order, took away and added what and how God commanded him. (Martin Luther, Table Talk #171; quoted in M. Reu, Luther and the Scriptures [Columbus, Ohio: Wartburg Press, 1944], p. 163)

I think many things had been written before Moses and that Moses took these things and added to them what God commanded him. No doubt he had the story of the creation from the tradition of the fathers. All in all, I believe that the preaching of the promised seed of Adam was greater before the Flood than the preaching of Christ is now. There must have been heretics then, too. (Martin Luther, Table Talk #291, Luther’s Works, Vol. 54 [Philadelphia: Fortress Press, 1967], pp. 40-41)

Genesis is the right book. One should read and learn it. There we see that the ancient patriarchs agree with our faith. In my opinion, however, Genesis was not by Moses, for there were books before his time and books are cited – for example, the Book of the Wars of the Lord and the Book of Jashar [cf. Num. 21:14; Josh. 10:13]. I believe that Adam wrote for several generations, and after him Noah and the rest, to describe what happened to them. (Martin Luther, Table Talk #4964, Luther’s Works, Vol. 54, p. 373)