What’s Up With the Ending?

At the end of the story, Frank Alpine hasn't discovered any illuminating answers to life's big questions, particularly why people suffer so much, but he makes a decision to accept suffering in a way that will engage and inspire him. He goes to the hospital to be circumcised, and after Passover he becomes a Jew. This change gives him a way forward, a way to live and suffer and love that gives these things meaning and power.