What are three quotes from Romeo and Juliet that address different love relationships?

Romeo describes his unrequited love for Rosaline to his kinsman, Benvolio, in Act I, Scene 1.  He says,

She'll not be hit

With Cupid's arrow.  She hath Dian's wit,

And, in strong proof of chastity well armed,

From love's weak childish bow she lives uncharmed (I.1.216-219).

He means that Roasline refuses to fall in love (which would happen if she were hit with the arrow of Cupid, the god of love).  Continuing the mythological allusions, Romeo says Rosaline is as chaste and clever as Diana.  Rosaline's heart simply cannot be touched by the arrows of love.  In fact, she has sworn to be a virgin forever, like the goddess Diana.  That his love remains unrequited makes Romeo utterly miserable.

Juliet describes romantic love in her balcony scene in Act II, Scene 2.  She says,

O Romeo, Romeo, wherefore art thou Romeo?

Deny thy father and refuse they name,

Or, if thou wilt not, be but sworn my love,

And I'll no longer be a Capulet (2.2.36-39).

Juliet's love is so strong that she is prepared to ask Romeo to give up his identity to be with her, or, if he is unwilling to do so, she will swear her love to him and give up her identity as a Capulet.  This romantic love becomes the most important thing to both of them, more important than friends or family honor and loyalty.  The fact that Juliet is willing to give up all she knows to be with Romeo is quite powerful.

Friar Lawrence also has a general love for everyone, and he wishes for peace and for the end of all feuding and violence.  When Romeo approaches the Friar with his wishes to marry Juliet, the Friar eventually agrees, saying, "this alliance may so happy prove / To turn your households' rancor to pure love" (II.3.98-99).  Friar Lawrence hopes this act of love between Romeo and Juliet will compel their families to stop their fighting, and he marries the couple out of his love for all humankind and his love of peace.