Schaff, Philip. History of the Christian Church (The Complete Eight Volumes in One). Amazon Kindle Edition, 2014.
Volume 2, Ante-Nicene Christianity A.D. 100-325, “Chapter 12. The Development of Catholic Theology in Conflict with Heresy” Sections 137-158, Loc. 18758-20235.
§ 151. Second Class of Antitrinitarians: Praxeas, Noetus, Callistus, Berryllus.
A second group of antitrinitarians, rather than seeing Christ as a merely powerful human, held to Christ’s deity but “sacrificed it to his independent personality, which they merged in the essence of the Father” (Schaff 2014, Loc. 19716). These teachers, according to Schaff, had some acceptance even in Rome, through the third century. Prominent among the antitrinitarians, was Praxeas, who, when confronted by Tertullian, was unable to explain adequately that his doctrine did not include the suffrering of God the Father (Schaff 2014, Loc. 19722). Noetus of Smyrna, active at the very start of the third century, held the same positions, viewing all nature to come together into one, an idea similar to that of Heraclitus (Schaff 2014, Loc. 19729). Pope Callistus I took on the views of Noetus, declaring the Son to be “merely the manifestation of the Father in human form” (Schaff 2014, Loc. 19736). For this reason, the Father also suffered on the cross. Schaff does note that much of this report comes from Hippolytus, who opposed Callistus vehemently. Finally, Berryllus of Bostra, according to the one passage found in Eusebius, “denied the personal pre-existence and in general the independent divinity of Christ, but at the same time asserted the indwelling of the divinity of the Father in him during his earthly life” (Schaff 2014, Loc. 19749). In a consultation in 244 with Origen in Arabia, he was corrected and convinced of his error.