Mohammed Awwad and his fiancée, both Muslims, recently found an affordable apartment for rent online in a town in Lebanon, southeast of Beirut. The 27-year-old journalist called the number and asked the owner when they could drop by to take a look. He was stunned by her response: Muslims are not allowed to settle in the town, she said. The apartment owner apologized to Awwad, saying she wouldn’t mind renting to people of any sect but officials in the town of Hadat issued orders years ago that only Christians be allowed to buy and rent property from the town’s Christian...