Jews and Christians alike have considered Moses, the great lawgiver and leader of the Hebrews at the time of the Exodus, the author of the first book in the Bible – Genesis. This conviction was challenged by pagan opponents a few times in the early Christian period but was never seriously doubted by any Christian or Jew up to about middle of the 18th century.
Jesus said that the Law was given by Moses (Mark 10:3; Luke 24:27; John 1:17). The context of the narrative (Mark 10:2–9) relating Jesus’ dispute with the Pharisees about the divine sanction of divorce makes it clear that He attributed to Moses the quotations taken from the first book in the Bible – Genesis. When His antagonists asked Him whether they had a right to divorce their wives, Jesus answered, “What did Moses command you?” In their reply the Pharisees referred to a provision made by Moses, found in Deut. 24:1–4, a passage from the fifth book of the Pentateuch. To this Christ replied that Moses had given them this precept because of the hardness of their heart, but that the earlier provisions had been different, and supported His statement by two other quotations from Moses (Gen. 1:27; 2:24).
The numerous quotations from the first book in the Bible -Genesis- that are found in the writings of the apostles show clearly that they were convinced that Moses wrote the book and that it was inspired (Rom. 4:17; Gal. 3:8; 4:30; Heb. 4:4; James 2:23).
And the Jewish tradition of the scribes, Christian fathers, and the conservative scholars to this day, confirm that Genesis was written by Moses. So, in view of this evidence the Christian may confidently believe that Moses was the author of the book of first book in the Bible.
In His service,