The loneliest Christmas I ever spent was in my grandfathers’ cottage near Sakogu, northern Ghana. I was just 15, and my parents and siblings were a thousand kilometers away. In previous years, when I had been with them and my village friends, Christmas was always big and memorable. But this Christmas was quiet and lonely. As I lay on my floor mat early Christmas morning, I remembered a local song: The year has ended; Christmas has come; the Son of God is born; peace and joy to everybody. Mournfully, I sang it over and over.

My grandmother came and asked, “What song…