A third-century presbyter named Sabellius began to emphasize in his church (probably in Rome) the oneness of God, as opposed to God’s tri-unity. In fact, Sabellius went so far as to say that there are no distinctions between the “persons” of the Godhead—the one God manifests Himself at different times and for different purposes in three different “modes” or “aspects.” This teaching, called “Sabellianism,” grew out of earlier forms of Modalistic Monarchianism.
None of the writings of Sabellius have survived to this day, so what we know of his teaching comes from the writings of those who refuted his errors. It seems that, according to Sabellianism, God manifested as the Father at creation, as the Son in redemption, and as the Spirit in sanctification. For years, Sabellianism was quite popular in some parts of the world, but it was finally declared a heresy, and Sabellius was excommunicated in AD 220.
One opponent of Sabellianism was Hippolytus of Rome, a contemporary of Sabellius. Hippolytus wrote against the heresy of Sabellianism in his Philosophumena (Refutation of All Heresies). Tertullian also strongly opposed Sabellianism, pointing out its error of Patripassianism (the teaching that the Father suffered with the Son on the cross). Other Christian leaders who had to fight against Sabellianism include Dionysius of Alexandria and Basil the Great. Sabellianism cropped up again during the time of the Reformation in the teaching of Michael Servetus and more recently in Swedenborgianism. Different labels, same lie.
Sabellian baptisms were performed in one name only, not in the name of the Father, Son, and Holy Spirit. Insisting upon a non-Trinitarian formula ignores Jesus’ words that emphasize God’s triune nature in Matthew 28:19, “Go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit.”
Sabellianism is an unbiblical denial of the eternal distinctions among the Persons of the Trinity. On one level, it is easy to see why Sabellianism has been so popular throughout the centuries—it is certainly much easier to understand Sabellianism than it is to understand the biblical doctrine of the Trinity. However, the Bible presents God as one God and also speaks of three Persons. As difficult as it is to understand, the Trinity is the truth. The Athanasian Creed puts it well: “We worship one God in Trinity, and Trinity in Unity; Neither confounding the persons nor dividing the substance. For there is one person of the Father, another of the Son, and another of the Holy Spirit. . . . So the Father is God, the Son is God, and the Holy Spirit is God; And yet they are not three Gods, but one God.”