He was reared as a Muslim in Indonesia and then belonged and attended a Black Liberation Theology church in Chicago for twenty years. A Christian would not have done that.
He also helped organized the Million Man March with Black Muslim Farrakhan. In a NY Times interview, he said the prettiest sound in the world is the Moslem call to prayer and proceeded to recite the words verbatim. I can think of many beautiful sounds in the world. What about a baby's cooing” a beautiful song, etc.