The doctrine of Tinitarian Monotheism appeared in the Athanasian Creed, formulated in the fourth century, which stated, “We worship on God in Trinity, and Trinity in Unity, neither confounding the Persons, nor dividing the Substance.” The church fathers used three important words to stress their belief in monotheism and Trinity: one, unity, and substance. They were careful to point out that God could not be divided into three parts (“dividing the substance”) and declared their belief in three persons who had an intrapersonal oneness within the one divine Being.
A popular liberal view is to liken the Trinity to H2O, which can be water, ice, or steam. The fallacy with this view is that God takes on three forms or modes.
The liberal theologians and philosophers from the eighteenth century through the first half of the twentieth century denied the supernatural as well as the inspiration of Scripture. The Trinity of the Godhead fell by the wayside. In the midst of these denials, the Swiss theologian Karl Barth published his commentary, Epistle to the Romans, in 1918. It fell as a thunderclap on a theological drought, meeting the liberals on their own ground. Though considered unorthodox in several of his views, Barth saved Christian theology. He solved the human predicament by attributing to God the power of immediate divine revelation to man and direct intervention in supernatural ways into human problems. He recovered some of the precious truth that was lost and pointed the way to a restudy of the whole theology of today among those still unprepared to accept inerrancy of Scripture.
The key to Barth’s study was a reexamination of the views of the early fathers on the Trinitarian problems. He laid down new doctrine on the work of the Holy Spirit and this led to examination of the definition of His Person. His concept of the Trinity is a threefold mode of divine existence or being, less than that of distinct persons but more than of mere modes of manifestation. Barth believed in the absolute deity of the Spirit. He declared, “The Holy Ghost is God the Lord in the fullness of Deity, in the total sovereignty and condescension, in the complete hiddenness and revealedness of God” (Karl Barth, The Holy Ghost and the Christian Life, 1:374).
American and British Neo-orthodoxy perpetuates the old distrust of the miraculous as far as Scriptural miracles are concerned, the work of God in extending grace to man, and in revealing Himself in a supernatural way. Two positions are held in Neo-orthodoxy; it denies the deity of the Holy Spirit or it denies that He is a Person. The key to the Neo-orthodox movement is that they cannot see how an infinite God can communicate with finite man. Therefore, they reject the concept that the Spirit of God speaks with authority either through the church, as held by the Roman Catholic Church, or in the Scriptures, as held by the Reformers (John F. Walvoord, The Holy Spirit, 260-265).