Take Responsibility

The Midrash Rabbah Berashis (19:12) says אָמַר רַבִּי אַבָּא בַּר כַּהֲנָא וְאָכַלְתִּי אֵין כְּתִיב כָּאן, אֶלָּא וָאֹכֵל, אכלתי ואוכל.  How do Chazal see in the possuk that Adam would sin again?  My great-grandfather says that the only way a person will stop sinning is if s/he acknowledges their mess up and sin.  If a person refuses to acknowledge they went wrong, then their is no hope for repentance. Adam didn't take responsibility for his sin, instead he blamed it on Chava,וַיֹּ֖אמֶר הָֽאָדָ֑ם הָֽאִשָּׁה֙ אֲשֶׁ֣ר נָתַ֣תָּה עִמָּדִ֔י הִ֛וא נָֽתְנָה־לִּ֥י מִן־הָעֵ֖ץ וָאֹכֵֽל.  It is in this lack of self blame that Chazal derive that Adam would sin again.

This same principle can explain the Gemorah in Yoma (22b) that Shaul Hamelech sinned only once but lost the kingship; Dovid sinned twice but was forgiven.  What's the difference between Dovid that was forgiven and Shaul that wasn't?  Dovid immediately admitted guilt when the prophet chastised him but Shaul denied any fault, to the contrary he said 'הקימותי את דבר ה (see Maharsha.)  It is accepting culpability for one's sin that is a prerequisite for teshuva.