Cain did not resemble Adam, and his descendants are not listed in the account of Adam’s descendants” (Targum Yonatan, Bereishit 42).

Cain said to Abel: "There is no justice, no Judge, no World to Come, and no reward and punishment for the righteous and the wicked.” Abel replied: "There is indeed justice, a Judge, a World to Come, and reward and punishment.” They argued this matter in the field. Then Cain rose up against his brother Abel, hit him in the forehead with a rock, and killed him” (Targum Yonatan, Bereishit 4:8).

The first book of the Bible has just been opened when Adam’s sons, Cain and Abel, competing for their father’s favor, engage in a fight that leads to the world’s first murder. Establishing a pattern that is repeated constantly in the Biblical text, and most famously in the case of Esau and Jacob, the offering of the younger son, Abel, is preferred to that of his elder brother, Cain.

The text itself does not tell us why Abel’s offering of the firstlings of his flock is more palatable to the Lord than Cain’s gift of fruit from the soil. We do learn that Cain is distraught, as the Almighty, speaking as intimately as a parent, counsels him, and suggests: "Why art thou wroth? and why is thy countenance fallen? If thou doest well, shall it not be lifted up? and if thou doest not well, sin coucheth at the door; and unto thee is its desire, but thou mayest rule over it."

Apparently Cain cannot control his terrestrial desires and his violent temper, adding another dimension of human frailty to God’s crown of creation. He seems, even at this earliest stage of human existence, preternaturally cynical. This characteristic is alluded to in the Midrash cited above. Cain feels bereft of God’s benevolence. He feels cheated, unrewarded for his labors, and jealously confronts his favored brother. Abel retorts: "There is no favoritism in Divine judgment. It is because my deeds are better than yours that my offering has been accepted." It is the bare honesty of Abel’s statment that strips Cain of his inner defenses. No longer able to believe in the goodness and justice of the world, he commits the greatest sin since the creation of the world, and like his parents who were exiled from the Garden of Eden, but even more similar to the narrative of Ishmael, becomes an outcast, an untouchable, disqualified from the genealogical tree of Adam and Eve.

Indeed, Cain is marked by God with a "sign," as he settles East of Eden in the land of Nod. The first child of the first couple receives the Lord’s harshest penalties. Cain is to earn his livelihood from the blood-soaked ground, which the Lord will not fertilize, and remain throughout his earthly existence both a fugitive and a wanderer. In this case, and in many Biblical accounts to follow, Cain’s guilt and punishment literally fit the crime.