What hypocrisies in Christianity and the Nation of Islam does Baldwin point out in "Down at the Cross"?

Elijah Muhammad was an African-American religious leader who led the Nation of Islam from 1934 until his death in 1975. The Nation of Islam was founded in Detroit by Wallace D. Fard Muhammad on July 4, 1930. Its stated goals are to improve the spiritual, mental, social, and economic condition of African Americans in the United States and all of humanity.