The Holy Spirit was thought to be a created being, created by the Son. Consubstantiality was denied. He was answered by Basil (On the Holy Spirit), Gregory of Nyssa (Against Eunomius, NPNF 2 IV, pp. 58–66), and Gregory Nazianzen (Orat. XXXI.12), who argued that the Holy Spirit was worthy of worship as God, and that the Spirit proceeds from the Father (John 15:26). . Tritheism misunderstands the Father, Son, and Spirit as if they were separate and distinct Gods, denying the unity of substance