That there are multiple authors of “Moses’ books” should not come as a surprise. A very quick look at the two creation accounts (Genesis 1; Genesis 2ff.) contrasts two entirely different literary styles and, more to the point, descriptions of God. Genesis 1 is patterned by men of the temple and clearly shows priestly influence. An impersonal and all powerful God creates order out of chaos, creates his universe in six days—from the lowest life forms to the highest (man)—and then, like any good observant priest, God rests on the seventh day. Wellhausen was the first to see “P” influence here: divine omnipotence, an orderly seven-day progression, and of course Sabbath observance.
The second creation account (Genesis 2:4ff) rewinds the film and starts all over again. Scholars believe that this account comes from the “J” or Yahwist tradition (the letters J and Y interrelate in translation). We have here an “anthropomorphic” God; he sounds and acts like a human being, carries on multiple discussions, “gets his hands dirty” and the like. In the J account God creates man first, and then goes on to create all the other kinds of wildlife in a valiant and compassionate effort to provide Adam with suitable companionship. Whether the authors intended this or not, there is a touch of humor in all this, but J is also a masterpiece of philosophy. God takes a rib from Adam, that is, from the middle of his body, as a sign that the new woman is neither lower nor higher in class, but his partner. J goes on to attempt to explain the origins of evil (the created snake), the reason why human work—farming in sweat around thorns and thistles—is man’s lot, and the strange power of sexual drive that a woman craves her man despite the pain and mortality of childbirth. Even with the catastrophic sin of the Garden of Eden, the J authors have successfully conveyed God’s love of humans as the climax of his creation.
It is helpful to remember that all of these traditions (including D and E) arose long after Israel had become a nation, and thus represent theological and philosophical thinking of a more modern people (relatively speaking). The Pentateuch as a whole—particularly Genesis—combines the most fragmentary history available from collective memory with the contributions of these thoughtful theologians/philosophers to create the compelling Biblical narratives we observe and celebrate in our liturgy. The ultimate content of Scripture is theological and not scientific.
I recall a retreat for priests years ago where the speaker observed the large number of canonized saints in Christendom. He elaborated that each was unique in temperament, style, philosophy and ministry, but that each reflected a special color in the perfect Jewel that is God. This is a good metaphor for our study of Scripture. It is the one God who has revealed himself to us in sacred revelation. As hearers of the Word we observe God as the distant stately master of universal chaos, the intimate confidante of Moses and David, the protagonist in the drama of Job, whose Son Jesus healed the sick and fed the hungry but cursed unproductive fig trees and proclaimed damnation to the unrepentant. In teaching the Scripture we cannot shop for an aspect of God we happen to like (or fear less). From Genesis to Revelation, we proclaim the fullness of God. Get to know Him. Our ancestors—J, D, E, P—set the template.