First name change in Torah (Along with Sarah)
How goodly are your tents, O Jacob, etc." To understand from the words of our Sages: Anyone who calls Abraham "Abram" transgresses a prohibition, as it is said, "Your name shall no longer be called Abram." Instead, from now on, one who calls [him] Jacob, [the verse continues] "For that is your name," [indicating] that here too, since there is an enhancement, the verse enhances it, etc. The idea is that it is impossible to come and reach the level of Israel without first passing through the attribute and level of Jacob. See further in Parashat Vayishlach, paragraph 104, side A
Next is from this week's Parsha, Parshas Vayishlach
Jacob was left alone. And a figure wrestled with him until the break of dawn.
In Genesis Rabbah 77:3, the Rabbis teach that this 'figure' is Esau's guardian angel
Genesis 32,26. “He said: ‘’let me go for dawn is breaking’”. A look at Rashi on this line reveals that he considers this a request by the spiritual alter-ego of Esau to take his turn in the heavenly choir praising the Lord in the world of the שרפים, disembodied creatures, every morning. The Midrash, (Bereshit Rabbah 78,2 and Chulin 91) commented that this “angel’s” turn to recite these praises of the Lord had not previously occurred so that he was most disturbed not to miss this opportunity of doing so. We need to understand why this angel’s turn to recite these praises of the Lord had come just then.
It seems that the spiritual representatives in heaven of all the nations sing the praises of the Lord. The timing of their doing so, usually coincides with whenever one of the nations on earth whom they represent in the celestial spheres, had performed an act of kindness for the Jewish people. This enables their respective representative at the heavenly court to act as a powerful advocate on behalf of their charges down on earth. Esau at that time had done a kindness for Yaakov, which enabled his celestial representative to stake his claim to take his turn in the lineup waiting to sing these praises in the heavenly choir. As this had been the first time Esau had done something kind for Yaakov, his spiritual representative had never yet had an opportunity to be part of that choir.
The Lubavicher Rebbe, Likutei Sichot, Vol. 3, pp. 795-789 (summary)
Whereas the Torah no longer refers to Abraham as Abram once his name has been changed, the Torah continues to refer to Jacob as both Jacob and Israel. This is because the name Israel was not meant to replace Jacob's original name but to complement it, expressing a new, loftier status that he now attained. Whereas "Jacob" had to struggle with Esau and use trickery to secure Issac's blessings of material bounty, these blessings were now conceded to "Israel" openly by Esau's guardian angel.
Jacob's two names represent two ways in which we interact with the world. Sometimes the material world or our own materialistic tendencies challenge our Divine consciousness or mission in life; we must then, like Jacob, struggle to reveal the Divinity that underlies the materiality of the world.
At other times, the world can be used as a means to enhance Divine consciousness or fulfill our Divine mission; at such times our challenge, like "Israel," is to use these opportunities both to bring the world to a higher level of Divine consciousness and to promote our own spiritual growth.