What are some quotes in Romeo and Juliet that show the harmful effects of prejudice?

Tybalt: "Uncle, this is a Montague, our foe, / a villain that is hither come in spite / To scorn at our solemnity this night" 1:5

Juliet: My only love sprung from my only hate! Too early seen unknown, and known too late! Prodigious birth of love it is to me, That I must love a loathed enemy.1:5