They are monophysists, so they consider Christ to be only God and not human. They do not admit the fourth Ecumenical council as well as the all the later councils.
Аггга... this reminds me of the "Are Mormons Christians?" debate that sometimes arises in US political culture, as in the case of Republican politician Mitt Romney. (Mormons believe in Christ, but they reject the definition of the "Trinity" from the Council of Nicea.)