A century before young men and women took to the streets of Tunisia, Egypt, Libya and other parts of the Arab world, demanding a new way of life and a new kind of politics, there was young Khalid, calling for a revolution of the spirit, a fusing of Islam and liberalism. He was the creation of Ameen Rihani, the author of “The Book of Khalid,” the first Arab American novel — and the first English-language novel by any Arab author. Rihani’s masterwork, published exactly 100 years ago, would inspire Kahlil Gibran’s “The Prophet,” published in 1923 and still one of...