No sooner had the Christian Church wrestled with the various forms of Arianism than the problem of the Pneumatomachians, those who fight against the Spirit required the apologetic skills of Orthodox-Catholic churchmen. St. Basil the Great (330-379) is the one most of us think of when we think of this controversy, and for good reason. His treatise On the Holy Spirit was instrumental in addressing this crisis. Pneumatomachians were so labeled because akin to how Arians did not believe the Son of God was fully God to the extent that he shared the essence of the Father, so Pneumatomachians did not believe the Holy Spirit was fully divine. There are practical implications, here. If the Spirit is not God and only God can save, what becomes of the sacraments?? Of course, the Orthodox Church is Trinitarian, as is her off-shoots, the Oriental Orthodox, the Roman Catholic Church, and the Assyrian Church of the East. Of course, the magisterial Protestant Churches and evangelicals and such are as well. It is only much much later that one runs into things such as Unitarianism and, later still, Oneness Pentecostalism.
Rather than highlight St. Basil’s arguments, I’d like to present a bit on what seems to have been the earliest such group, the “Tropici” in Egypt. They existed in the Thmuitian diocese. Thmuis itself sat to the east-northeast of Alexandria and was a major city at the time. The city died off much later during Islamic rule, so don’t expect to find it on a map now. St. Sarapion of Thmuis wrote to St. Athanasios asking for advice and insights. This led to St. Athanasios’ letters to Sarapion in which Athanasios argued against the Tropici’s position. Athanasios labeled the group Tropici because their argument depended upon biblical “tropes.” Of course, Athanasios and his Orthodox-Catholic supporters had been doing the same thing, but the difference is they had been doing so on the basis of the rule of faith. The real objection is not tropes, but whether they are faithful tropes. If not, your group may be labeled “Tropici.”
The Tropici used two main verses to argue their case:
1) Amos 4.13 (“I am He that establishes thunder and creates spirit and declares to men His Christ.”)
2) 1 Timothy 5.21 (“in the presence of God and of Christ Jesus and of the elect angels”).
Athanasios offered the following arguments against the Tropici’s misinterpretation of these verses:
1) With regard to Amos 4.13, Athanasios notes that since the Tropici do not think that Proverbs 8.22 talks about a temporal creation of the Son, neither should they think this passage speaks of the creation of the Holy Spirit. In fact, this passage does not speak of the Holy Spirit because “of God,” “of the Father,” or “my” or “of Christ,” or “of the Son” is not also included in this verse.
2) With respect to the Holy Spirit being an angel, Athanasios notes that nowhere in the Bible is the Spirit called an angel or an archangel, though he is called the Spirit of God and the Spirit of Christ. Athanasios even claims that the Holy Spirit is ministered to by an angel when Gabriel announces to Mary: “The Holy Spirit shall come upon you and the Power of the Highest shall overshadow you” [Lk 1.35]. And if that doesn’t convince the Tropici, Athanasios asks how they say one of the angels is the Spirit since they are all mentioned. They are not all one being. Which one is the Holy Spirit?
In addition to the exegetical or interpretive aspect of the debate, the Tropici also claimed if the Spirit proceeds directly from the Father, then there are two sons who are brothers, but if the Spirit comes from the Son, then being produced by the Father and the Son, He must be a grandson of the Father.
Athanasios responded by saying that we must hold to the biblical terms as they’ve been revealed. If the Tropici are going to be so materialistic in their use of the terms and analogies, then who is the father of the Father? For which father is not also a son? “Just as we cannot ascribe a father to the Father, so neither can we ascribe a brother to the Son. Other than the Father, as we have written already, there is no God. … For the Spirit is not given the name of son in the Scriptures, lest he be taken for a brother; nor son of the Son, lest the Father be thought to be a grandfather. … It is enough to know that the Spirit is not a creature” [Letters to Sarapion 1.16].