There is 2 ways to serve Hashem Love or Fear, in truth both are Love, conventual love is about my feeling it’s about feeling myself, however fear (nullifying yourself) is exposing yourself before hashem and allowing Hashem in beyond yourself much deeper level of love and connection,Yitzchok served Hashem with fear yet had the closest connection and love to Hashem.

לקו״ש ל

Although other nations can also have self sacrifice it’s based off their intellect and feeling and is greater expression of self, however Avrohom and by inheritance every Jews sacrifice is beyond intellect and feeling total self sacrifice just for Hashem. לקו״ש כ -ג

Although Rosh Hashanah we come together as one as our soul connects to its source to coronate hashem as king it’s Yom kipper that we actualize this unity soul in a body where we do see differences and despite our differences we come together as one completing the coronation of hashem as our king.

לקו״ש יט

On Rosh Hashanah when we are at our best we enter a covenant with hashem to always love and take care of us by first standing before him all as one from the leaders to the water carriers by behaving in a super rational way hashem responds the same.

לקו״ש ב