why does friar laurence agree to marry romeo and juliet?

Friar Laurence agrees to marry Romeo and Juliet because he hopes that their marriage will help bring peace and end the long-standing feud between the Montague and Capulet families. Although he initially hesitates due to Romeo's sudden shift of affection from Rosaline to Juliet, Friar Laurence ultimately consents, seeing their union as a potential way to reconcile the two families and transform the hate into love. He also acts out of compassion, wanting to help the young couple who trust him with their secret and love.