We’ve read about it for millennia. A man, handsome in form and appearance, ascends to one of the highest ranks within the government. While in a position of power he has the opportunity to sleep with a married woman. Up to this point, we could be speaking about either General Petraeus or Joseph. Both men seemingly had it all and both men made decisions that hindered their careers.
The Torah tells us that Joseph ran Potiphar’s household. Potiphar was the head of Pharaoh’s guard. Joseph, who was not married, rebuffs the advances of Potiphar’s wife. Joseph’s decision not to sleep with Potiphar’s wife costs Joseph his job and lands him in jail after Potiphar’s wife accuses Joseph of trying to rape her. (Genesis 39:1-20.)
Joseph understood that Potiphar had treated Joseph as an equal and had given Joseph everything within Potiphar’s household – everything except Potiphar’s wife. In refusing to sleep with Potiphar’s wife, Joseph asked rhetorically, “How then can I do this great wickedness, and sin against God?” (Genesis 39:9.)
One reading of this verse is that the “sin against God” Joseph referred to is the sin of sleeping with a married man’s wife. But, regardless of what sin Joseph is describing, how did Joseph know what constituted a sin against God? After all, Joseph lived before God gave the Torah.
One traditional Karaite explanation is that mankind possesses a baseline morality helping to distinguish between right and wrong. According to that Karaite view, this baseline morality arose when Adam and Eve ate from the “tree of knowledge of good and evil” in the Garden of Eden. (Genesis 3:1-7.)
We all inherently know that cheating on a spouse and sleeping with someone else’s spouse are sins, but this Karaite interpretation explains how we know.