In this film Jake struggles with his mothers disowning of his brother who married a non-Jewish girl. He thinks that if he does the same thing that his mother and the church congregation will disapprove. He shows his maturity and growing up by announcing to the whole assembly that he was in love with Anna.
Brian faced a much different but much the same challenges or crisis. He is a priest that thinks he is in love with Anna. He struggles with this when it is discovered that Anna does not feel the same way. He has difficulty with this partly because his friend Jake hurt her like he hurt all the others, but also partly because he almost left his faith for a girl. He shows his maturity after this by accepting the relationship between Jake and Anna, and he is more devoted to his faith now than ever.
Anna went through something I think all of us must go through, how far are you willing to go for another person? She begins a relationship with a rabbi who can only and has so far only dated Jewish women. He never asked her to be Jewish however, she started to take classes and begins the process of becoming Jewish. She shows her maturity because she begins to search for her faith.