This theology is commonly called Arianism , but there are many varieties of this form of Unitarianism . They range from the belief that the Son , before he came to earth , was a divine spirit of the same nature as God to the belief that he was an angel or other lesser spirit creature of a wholly different nature from God . This theology is commonly called Arianism ; however , there are many varieties of this form of Unitarianism , ranging from the belief that the Son was a divine spirit of the same nature as God before coming to earth , to the belief that he was an angel or other lesser spirit creature of a wholly different nature from God .