By PETER SMITHWhen Amy-Jill Levine was a child in Massachusetts, a schoolmate in her predominantly Catholic hometown told her she was guilty of killing Christ because she was Jewish. Her mother reassured her that wasn’t the case — and instead of being embittered by the encounter, the young Levine began attending a Catholic catechism class to learn more about her Christian neighbors and their beliefs. That blossomed into a decades-long academic career in an unusual role — a Jewish scholar of Christian Scriptures. Levine has worked to improve how Christians and her fellow Jews understand each other. She’s spoken at...