The Maximum Leader points out several groups that claim membership in the Christian fraternity yet deny the divinity of Jesus. He specifically mentions Mormons, Jehovah’s Witnesses, and Christian Scientists.
Members of each of these groups may consider themselves to be Christian. But they are not Christians according to the definitions of mainstream Christianity. Many mainstream Christians specifically deny membership in the fraternity to their groups.
Google searches for:
“Christian Science” + Cult = 48,300 hits.
“Jehovah’s Witnesses” + Cult = 50,600 hits.
Mormons + Cult = 51,700 hits.
I’m passing no judgment here. And many of the links provided by Google are lacking in, shall we say, Christian charity. But certainly a good proportion of the Christian world does not view those groups as “Christian.”
Perhaps it would be better to call each of those groups “Post-Christian.”
All three are unique products of the American experience - the Second Great Awakening and the humanism of the Antebellum period.
All three rely heavily on the teachings of a new prophet - Mary Baker Eddy, Charles Taze Russell, and Joseph Smith.
All three have works that supercede the Bible - “Science and Health” and “The Book of Mormon” both claim to be divinely inspired and infallible. I am not sure if the Witnesses ascribe divine revelation to Russell.
In many ways, if the Maximum Leader want to include these groups in the fold, he would do well to include Muslims as well. The Muslims accept the teachings of the Bible as incomplete, have a new prophet, and subscribe to a new testament.