Naso 

In parshas Nasso is recorded the Birchas Kohanim, the Priestly Benediction. The benediction is a powerful and beautiful blessing that expresses Hashem’s greatest blessings upon the Jewish People. The Kohanim have the responsibility and honor to serve as Hashem’s messengers to impart these special blessings to His people.

The Zohar says that any Kohen that does not love the congregation should not participate in Birchas Kohanim. This is because of the verse, טוב עין הוא יבורך – “He with a good eye should be blessed (proverbs 22:9).”

The Zohar says, do not read that, “He with a good eye shall be blessed,” rather read, “He with a good eye shall bless others.”
(זח”ג קמז,ב)
The Shulchan Aruch – Code of Jewish law based on the above Zohar instructs that a Kohen who (God forbid)  hates a congregant should actually leave shul so as not to  do Birchas Kohanim, since saying Birchas Cohanim while hating a congregant is dangerous for the Kohen.
The Zohar brings a story of a Kohen who once stood up to say Birchas Kohanim, and before he finished he became a pile of bones. The reason, the Zohar explains, is that he did not bless from love!
(זהר פרשת נשא קמז,ב ,שלחן ערוך הרב סי’ קכח סעי’ יט)

This is of course a lesson for all the Jewish people to be careful not to hate each other.
One of the 613 commandments is “Do Not hate your fellow in your heart”

In the Amida we say in teh final blessing of peace – “Bless us our Father all of us as one”
In other words we cant receive the blessings of “Life, Grace, Kindness, mercy etc” unless we are all united.

Interestingly the last word of the Priestly Blessing is also Shalom

For all blessing can only flow through peace
Shabbat Shalom!