The Forty Rules of Love by Elif Shafak
Ella Rubenstein is forty years old and unhappily married when she takes a job as a reader for a literary agent. Her first assignment is to read and report on Sweet Blasphemy, a novel written by a man named Aziz Zahara. Ella is mesmerized by his tale of Shams's search for Rumi and the dervish's role in transforming the successful but unhappy cleric into a committed mystic, passionate poet, and advocate of love. She is also taken with Shams's lessons, or rules, that offer insight into an ancient philosophy based on the unity of all people and religions, and the presence of love in each and every one of us.