As East of Eden’s title indicates, Steinbeck’s novel draws inspiration from the Book of Genesis. This text is the first book of the Jewish Torah and the Christian Bible, and it contains stories about the origins of the universe and humanity. In the Book of Genesis, God creates the first two humans, Adam and Eve, and places them in the paradisical Garden of Eden, which meets all of their needs without them having to labor. God grants Adam and Eve free will but warns them that there are consequences to misusing this gift: “You are free to eat from any tree in the garden; but you must not eat from the tree of the knowledge of good and evil, for when you eat from it you will certainly die” (Genesis 2:16-17). However, a serpent, which Christians interpret as the devil, tempts Eve to eat the tree’s fruit. In turn, she persuades Adam to eat it as well. As punishment, God casts Adam and Eve out of Eden, makes childbirth painful, and changes the land so that growing food requires “painful toil.” Thus, the story explains both humans’ flawed nature and life’s hardships. Writers have referenced and reinterpreted these stories for millennia, making them highly influential in Western culture. As Cathy's dehumanizing portrayal in the novel illustrates, one of the effects of this legacy is a prejudicial association between women and immorality, and the misuse of Eve’s story to provide “biblical rationale for patriarchal cultures throughout history” (Drew, Arlyn. “Unbinding Genesis 3:16: A Theocentric Critique of Sex-Based Power,” Andrews University, 6 Oct. 2024). Steinbeck’s novel also connects to Adam and Eve’s story through Adam Trask’s dream of creating an Eden on earth, a goal that illuminates how his idealism tragically prevents him from accepting reality.

East of Eden takes particular interest in the story of Adam and Eve’s sons, Cain and Abel. In Genesis Chapter 4, the two brothers make sacrifices to God. Cain, a farmer, offers produce, while Abel, a shepherd, offers his flock’s firstborn. When God favors Abel’s offering, Cain murders him out of jealousy. God punishes Cain for committing the first ever murder by making him a “restless wanderer on the earth,” leading him to settle “east of Eden” (Genesis 4:12, 16).  In addition, God places a “mark” on Cain’s forehead to ensure that no one will kill him in retribution. In the novel, the scars on Cathy and Charles’s foreheads allude to this “Mark of Cain,” signaling their status as characters associated with wrongdoing. However, while the novel's characters echo the biblical figures who share their initials, Steinbeck adds complexity to his depiction of fraught fraternal relationships. For example, he exposes how Adam and Aron’s “goodness” leads to flaws of naivety and intolerance for others’ shortcomings while Charles and Cal’s “badness” allow them to engage with the world more effectively. The Book of Genesis strongly influences the novel’s structure, characters, and themes of free will and human nature.