וקרא לך שם חדש אשר פי ה' יקבנו ... (ישעי' סב-ב)
Yeshaya HaNavi proclaims that the “Nations shall see your victory ... and you shall be called by a new name that Hashem shall bestow.” R’ Yonason Eibschutz zt”l wonders about this, and quotes Chazal who teach us that in the future, Hashem will ask the Avos why Klal Yisroel should be redeemed, saying “your children are sinners.” While Avraham and Yaakov Avinu offer varying excuses, Yitzchok Avinu’s answer is perplexing in that he “reproaches” Hashem and counters that Klal Yisroel are not just his own children, but rather we are the children of Hashem as well.
It is possible to say that Yitzchok Avinu’s response to Hashem touches on a deeper point. As descendants of the Avos, we are infused with their qualities and attributes. Avraham exemplified the middah of חסד (kindness), Yitzchok was גבורה (strength), and Yaakov Avinu perfected the attribute of אמת (honesty). While Klal Yisroel personifies all three, the attribute of גבורה - strength, is one that requires more intense focus and effort to achieve, and a Jew needs to exert copious amounts of energy to achieve true strength.
Thus, Yitzchok Avinu’s answer reveals that true גבורה not only requires a Jew’s personal determination; it also requires the Almighty’s assistance to infuse him with a Divine strength. This explains Yeshaya’s proclamation in that when we take a step closer to Hashem and display strength to repel sin, Hashem infuses us with His strength making us as though we have been reborn with a new name and identity.