Hippolytus of Rome is among the earliest orthodox church fathers to defend classical trinitarianism against classical modalism when it became an issue in the late second and early third centuries. Sabellius himself stayed at Rome; Hippolytus directed his treatise against Noetus, another classical modalist.
Sabellius and Noetus, however, were not bishops, and Sabellius was condemned by council for his heresy. But the church of Rome’s problems with modalism were not over; the bishops of Rome themselves, Popes Zephyrinus and Callixtus, were classical modalists, and for this reason were strongly opposed by Hippolytus.
Hippolytus was elected as a rival bishop of Rome, and continued to oppose the papacy. During a period of peresecution Hippolytus was enslaved and put to hard labor in Roman mines, likely dying as a martyr.
Hippolytus wrote much in opposition to modalism; his teaching the classical doctrine that the one God of the Christian faith is the Father was only a small part of that. On that point he wrote:
“For it is right, in the first place, to expound the truth that the Father is one God, “of whom is every family,” “by whom are all things, of whom are all things, and we in Him.”” Against the Heresy of One Noetus, 3.
“If, therefore, all things are put under Him with the exception of Him who put them under Him, He is Lord of all, and the Father is Lord of Him, that in all there might be manifested one God, to whom all things are made subject together with Christ, to whom the Father hath made all things subject, with the exception of Himself. And this, indeed, is said by Christ Himself, as when in the Gospel He confessed Him to be His Father and His God. For He speaks thus: “I go to my Father and your Father, and to my God and your God.”” Against the Heresy of One Noetus, 6.
With these brief statements Hippolytus adds his name to a long list of early Christian theologians who articulated this scriptural truth. For more quotes on this topic, see I believe in one God, the Father Almighty