If you do good, it shall be forgiven you; and if you do not do good, (your) sin is retained until the day of judgment; recompense will be required of you if you do not do good; but if you do good, it will be forgiven you.In the Targum for this verse (which reflects a first-century Judean understanding of the text) Cain is offered the chance to repent. The terms of repentance offered Cain are:
- He can do good. Doing good shows his repentance. Doing the right thing is what God asked Cain to do.
- Doing good brings a remission or forgiveness of his sins. The Aramaic term here, yištabêq, is the same verb used in the Aramaic version of Psalm 22:1 that Jesus quotes on the cross (the sabachthani in Matthew 27:46), and means to abandon, to desert, or to forgive. If we abandon our sins, God will abandon them as well. Forgiveness in Genesis 4:7 is God abandoning our sins and abandoning keeping track of them. They are not retained for the day of judgment.
- If he does not do good, his sin is retained and he is not rid of it, and it will come back to him at the day of judgment.
Cain, however, chose not only to hang on to his sins but magnify them. His envy of Abel, who did well and was accepted, caused him to betray and murder Abel. When confronted with his iniquitous deed, Cain denied it, and rationalized it. He did not even try to repent of his treachery against his more righteous brother.
The Targum does not supply a motive for Cain's actions. The Book of Moses, however, does:
And Cain gloried in that which he had done, saying: I am free; surely the flocks of my brother falleth into my hands (Moses 5:33).Cain thought that being rid of his pesky righteous brother would make him somehow free to pursue his own agenda. He also confiscated his brother's possessions that he had labored to acquire. They were now his to do with as he pleased. Cain sold his soul for a few flocks.
So in the end, if Cain was a lost cause, his own choices and his own sins made him so.