One of the most influential forms of modalism, known as Sabellianism, argued for the following way of understanding the Trinity.
1. The one God is revealed in the manner of creator and lawgiver. This aspect of God is referred to as “the Father.”
2. The same God is then revealed in the manner of savior, in the person of Jesus Christ. This aspect of God is referred to as “the Son.”
3. The same God is then revealed in the manner of the one who sanctifies and gives eternal life. This aspect of God is referred to as “the Spirit.”
There is thus no difference between the three persons of the Trinity, except for their appear- ance and chronological location. For modalism, the one God is revealed in three different ways at different points in salvation history.
The doctrines of the Trinity which emerged in the early fourth century reasserted the “triunity” of God, moving away from modalism. The work of the Cappadocian Fathers in the eastern church and Augustine of Hippo in the western church did much to consoli- date the doctrine of the Trinity. The traditional Trinitarian vocabulary – with its core notions of as “person,” “nature,” “essence,” and “substance” – allowed the theologians of the early church to affirm the fundamental unity of God, while celebrating the richness of God’s relationship with the creation. Differences emerged between eastern and western approaches to the Trinity, particularly over the question of the Holy Spirit. Did the Spirit proceed from the Father alone (Basil the Great), or from the Father and the Son (Augus- tine)? This simmering disagreement would eventually lead to a debate between the eastern and western churches, which would create still further tensions between them, and make no small contribution to the “Great Schism” of 1054 (2.1.10).