We will celebrate the event with an official coronation ceremony. The prayers of the day speak about our acceptance of Hashem's sovereignty. We are His holy nation. Or, is a nation a unified group, like the bundle of twigs. This is our purpose this Rosh Hashanah, to promote national unity within the Jewish people.
Unity means getting along with others.
Rosh Hashanah is a day when we make special efforts to love all Jews. The last thing we want to do is to make an argument. Even if someone does something wrong, today is not the day to quarrel about it. Give in to the other person. That is the spirit of Rosh Hashanah.