Compare the expulsion of Adam and Eve from the Garden of Eden with the story of Equality 7-2521 in Anthem.
Ayn Rand, the author, was an atheist who believed that religions used sin as a way to manipulate people into behaving as they saw fit. Accordingly, she felt that any god also used sin to manipulate people from acting or behaving with logical reasoning (common sense); so, the parallels between the Adam and Eve story and Equality and Liberty are certainly drawn in Anthem. The only way that Equality could achieve his own personal greatness and educate himself about the things he was interested in was to leave the society that held him back. So what was holding back Adam and Eve in the Garden of Eden? The lack of knowledge--the same thing that was holding Equality back. By eating of the fruit of the tree of knowledge (of good and evil), Adam and Eve gained knowledge. People can't remain in a place of ignorance once they have gained knowledge. Metaphorically speaking, a person cannot return to ignorance when knowledge is gained; therefore, the removal of Adam from Eden and Equality from the city is like one's removal from ignorance to knowledge. Being in a place, or state of being, that limits knowledge is stifling and a person cannot grow or reach one's full potential--as is the case with both Adam and Equality.