That depends on how you define Christian. I define Christian as one who accepts Scripture (Both Old and New Testaments) as the absolute standard of authority and EVERYTHING that contradicts Scripture as a lie or an error.
This acceptance must go beyond mental assent and be the basis for both faith and lifestyle.
I believe that this definition includes all the essential beliefs , doctrine and teachings necessary for Salvation.
I also believe that this definition excludes the teachings of the RCC, Mormons, JWs, and Jewish Roots Movement, among others.