Had they repented properly, Adam and Eve would have been forgiven and been allowed to remain in the Garden of Eden. But since they did not rise to the occasion, they were banished from it. Their firstborn child, Cain, was presented with a similar opportunity after killing his brother Abel when G d accepted Abel’s offering but not Cain’s.
Learning from Failures
הֲלוֹא אִם תֵּיטִיב שְׂאֵת וגו': (בראשית ד:ז)
[G‑d told Cain,] “If you improve, you will be forgiven.” Genesis 4:7

Cain’s true failure was that he did not learn from G‑d’s positive response to Abel, who had offered up the choicest of his animals. Had Cain presented a second offering, this time from the choicest of his crop, G‑d would have forgiven him and accepted it. G‑d here tried to teach him that if an individual learns from his errors, his slate can be wiped clean. However, Cain refused to admit his error. Convinced of the rightness of his action, he felt that if Abel were eliminated, his own view would necessarily prevail.

Our challenge, as well, is to learn from our failures, rather than to stubbornly refuse to admit them and even rationalize them. By learning from our failures, we can transform every one of them into an impetus for further spiritual growth.1