MODALISM

At various times people have taught that God is not really three distinct persons, but only one person who appears to people in different "modes" at different times. For example, in the Old Testament God appeared as "Father." Throughout the Gospels, this same divine person appeared as "the Son" as seen in the human life and ministry of Jesus. After Pentecost, this same person then revealed himself as the "Spirit" active in the church.

This teaching is also referred to by two other names. Sometimes it is called Sabellianism, after a teacher named Sabellius who lived in Rome in the early third century A.D. Another term for modalism is "modalistic monarchianism," because this teaching not only says that God revealed himself in different "modes" but it also says that there is only one supreme ruler ("monarch") in the universe and that is God himself, who consists of only one person.

Modalism gains its attractiveness from the desire to emphasize clearly the fact that there is only one God. It may claim support not only from the passages talking about one God, but also from passages such as John 10:30 ("I and the Father are one") and simply mean that Jesus fully reveals the character of God the Father, and the former passage (John 10:30), in a context in which Jesus affirms that he will accomplish all that the Father has given him to do and save all whom the Father has given to him, seems to mean that Jesus and the Father are one in purpose (though it may also imply oneness of essence).

The fatal shortcoming of modalism is the fact that it must deny the personal relationships within the Trinity that appear in so many places in Scripture (or it must affirm that these were simply an illusion and not real). Thus, it must deny three separate persons at the baptism of Jesus, where the Father speaks from heaven and the Spirit descends on Jesus like a dove. And it must say that all those instances where Jesus is praying to the Father are an illusion or a charade. The idea of the Son or the Holy Spirit interceding for us before God the Father is lost. Finally, modalism ultimately loses the heart of the doctrine of the atonement-that is, the idea that God sent his Son as a substitutionary sacrifice, and that the Son bore the wrath of God in our place, and that the Father, representing the interests of the Trinity, saw the suffering of Christ and was satisfied (Isaiah 53:11)

Moreover, modalism denies the independence of God, for if God is only one person, then he has no ability to love and to communicate without other persons in his creation. Therefore it was necessary for God to create the world, and God would no longer be independent of creation.

One present denomination within Protestantism, the United Pentecostal Church, is modalistic in its doctrinal position.

From Wayne Grudem's Systematic Theology An Introduction to Biblical Doctrine