In Jewish singer Meilech Kohn's song, "Veuhavtu", he expresses an interesting thought in the lyrics:
.יעדער איינער דאווענט און בעט און מ'ווארט פאר משיח, ער וועט נאר קומען ווען מיר פארטראגן זיך
"Everyone prays and begs and waits for Moshiach; he will only come when we all get along."
This is a nice idea, however, I've never heard it expressed in any sources. Is there a source for this idea, that through the mitzvah of ואהבת לרעך כמוך we can merit Moshiach?
By the way, an a capella version of the song can be found here from Ari Goldwag.