The Historical Background
Sabellius, a third-century theologian and priest, was a proponent of modalism. Modalism is a non-Trinitarian heresy claiming that the Father, Son and Holy Spirit are simply different modes of God and not distinct persons within the Godhead. Little is known about Sabellius, who was excommunicated in 220 AD, but the teaching attached to his name became infamous and is still with us today.
Sabellius’ View of God
The modalists were rightly concerned with maintaining the oneness of God as well as the full deity of Christ. However, this led them to the error of seeing any suggestion that the Son was a distinct person from the Father as creating a duality within the Godhead. Early historian Hippolytus summarized the modalist position as one in which the names “Father,” “Son,” and “Holy Spirit” did not stand for real distinctions in the Godhead, but rather mere names that described the actions of the one God at different times in history. In other words, “Father,” “Son,” and “Spirit” are merely adjectives describing how the one divine Being acts and is perceived. Sabellius used the analogy of the sun to explain his position. In the same way that the sun gives off both light and heat, so also the single divine being radiates in history in different fashions. In creation, the divine Being acts as Father; in redemption, as Son; in the lives of believers, as the Holy Spirit.
The Orthodox Response
The orthodox response to the heresy of Sabellius (and other modalists) came from Tertullian, the African theologian. In Against Praxeas, Tertullian argued that Scripture reveals that the Godhead is three who are at the same time one. He rightly considered this an essential doctrine of Christianity. In the Sabellian modalist view, the three are not anything real, but rather just different manifestations of the one. Therefore, Tertullian proposed that we speak of the Godhead as “one substance (substantia) consisting in three persons (persona).” This terminology would serve as the basis for future Latin theology, and it is from Tertullian’s pen that the important Christian word “Trinity” (trinitas) was first inked.
Why Does All This Matter?
Sabellianism is one of the heresies in Christendom that keeps appearing again and again in different forms. Anyone who has sat in a Sunday School class and heard that God’s Tri-unity is like water in that it appears to us in three forms (liquid, steam, and ice) has been exposed to a contemporary variation of modalism. God is not one person that exists in three different forms at three different times, but three distinct persons concurrently sharing one common essence.
Modalism also reared its ugly head in the classic liberal theology of Friedrich Schleiermacher, and it is even seen today in the “Oneness” sect of Pentecostalism, which clearly denies the doctrine of the Trinity. What is at stake in the debate is not merely fancy theological terminology, but our understanding of God himself. For example, if Sabellian modalism were true, the intimate relationship that existed between the Father and the Son from all eternity (John 17) would be irrational. Modalism undercuts the atoning work of Jesus Christ, as well. If there is only one God who works in different modes of being throughout history, one must question whether Jesus Christ was truly a man, or if he only appeared to be such, as the heresy of Docetism declares. If Jesus Christ is not fully God and fully man, then he cannot be the one mediator between God and man. It is for this reason that the heresy of Sabellian modalism must be rejected, and the biblical doctrine of the Trinity must be affirmed.