The Friar agrees to marry Romeo and Juliet because he believes that their marriage will end the feud between their families. He also wants to help Romeo and Juliet because they are so in love with each other, so he knows that their marriage will make them both happy. The Friar knows that Romeo and Juliet’s marriage will make their families happy as well, which is another reason why he agrees to marry them. He knows that Romeo’s family will be happy because they won’t have to worry about losing the feud anymore, and he knows that Juliet’s family will be happy because they won’t have to worry about her being married off against her will. The Friar also believes that bringing peace to Verona is important—and marrying Romeo and Juliet would certainly do that! The Friar knows that Romeo and Juliet are willing to risk everything for their love—including their lives! They are willing to give up everything for each other—their lives, their families’ happiness, even Verona’s peace—just so long as they can be together forever as husband and wife. They show through this act of selflessness how much they love each other.