According to the Bible, Cain was the first murderer in history, committing a sin not only against God but against another human being because he felt unloved. After strife between man and God in Eden, here was strife between man and man; the filial bond is stressed time and again in the sixteen Bible verses, Although the Bible gives no reason for why God chooses Abel's sacrifice over Cain's, Cain's violence is sparked by anger at the rejection of his gift, and jealousy and resentment toward his brother. As a result, not only does he kill, he lies. As punishment, he is condemned to "till the ground" fruitlessly and to be "a restless wanderer." His mark is not a curse, but a protective sign of God's enduring care.
We Are All Descendants of Cain
Cain, in his wanderings, still has free will to conquer his basic instincts, to choose right from wrong. "'Sin is crouching at the door hungry to get you. You can still master him,' God has told him." We are all descendants of Cain—Abel had none—and possess free will in the struggle between good and evil within us. Condemned by neither nature nor nurture to be one way or another, we all create our destinies by choosing between virtue and vice.
As the narrator in Part Four of East of Eden says: "Humans are caught—in their lives, in their thoughts, in their hungers and ambitions, in their avarice and cruelty, and in their kindness and generosity too—in a net of good and evil. ...We have only one story. All novels, all poetry, are built on the never-ending contest in ourselves of good and evil. And it occurs to me that evil must constantly re-spawn, while good, while virtue is venerable as nothing else in the world is."
- Journal of a Novel: The East of Eden Letters by John Steinbeck (The Viking Press, Inc.,1969; Penguin Books, 1990)
- The Bible As It Was by James L. Kugel (Cambridge: Harvard University Press, 1997)