The message of togetherness is the essence of the holiday of Purim. I heard the following from Rav Dovid Ostroff:
The S'fas Emes says that when B'nei Yisroel (the Jewish people) are united, Amalek (Haman) does not have a hold on them. It is when they are separated and don't have unity, that the enemy can attack them. Haman told Achashveirosh to wipe out the Jewish nation, to which he replied that he cannot, as all nations that attempted to do so were wiped from the face of the earth. Haman countered that the Jews were not unified.
So Mordechai said to gather them, make unity amongst the Jews, and they became unified because Mordechai showed great love for them even though they partied with Achashveirosh and bowed down to idols (which he had warned them not to do).
Our unity is our strength, and the removal of our arrogance, which puts walls between us is our main task.
When the Jewish people saw how much Hashem loved them during their time of strife and despite their not behaving themselves they accepted the Torah with a total love that they didn't have when they "received it" on mount sinai out of fear.
We only know someones true love for us when we see them demonstrate it in hard circumstances. It will be our total and love and acceptance of each other that will make the future ge'ulah (redemption) so magnificent that it will dwarf the nissim (miracles) of yetsias mitzrayim (the coming out of Egypt). May we see it soon!
Dr. Zev Ballen