Servetus states his view clearly in the preamble to Restoration of Christianity (1553): "There is nothing greater, reader, than to recognize that God has been manifested as substance, and that His divine nature has been truly communicated.
This theology, though original in some respects, has often been compared to Adoptionism, Arianism, and Sabellianism, all of which Trinitarians rejected in favour of the belief that God exists eternally in three distinct persons.