Answer
One of the key questions in Christian thought is, how does the language of the New Testament fit into the later developed language of Trinitarianism? And then as we read through the New Testament, it looks like fairly early the apostles were confessing belief in a God who is triune. At least they use language that seems to imply that. Nobody questions the deity of the Father; no Christian questions the deity of the Son. But when the New Testament writers describe the Spirit, they describe him, they use language for him, that is consistent with the language that makes its way into creedal confessions that he is God like the Father and the Son are God. Each one of the Epistles, with the exception maybe of 2 John, uses language at the very beginning—prior to the body of the letter, prior to developing the argument—in the grieving section, the apostles use language that sounds very Trinitarian. But maybe the strongest argument for the deity of the Spirit is found in the language of a benediction like in 1 Corinthians 13 where the apostle Paul praises the Lord Jesus Christ for his grace, the love of God and the fellowship of the Holy Spirit, and Ephesians 1, that extended argument where he praises the work of the Father, then the Son and the Spirit, and the baptismal formula in Matthew 28 where Jesus says make disciples, baptizing them in the name of the Father, Son and Spirit. And that language, which sounds very confessional, it sounds almost creedal is language that's rooted in the New Testament long before Nicea, long before the language of the creeds was developed. So, it seems to me that that language implies an early understanding of the Spirit as a third person of the Godhead, and that in confession and in the introduction of writing, and in the content itself, the Epistles were defending not only a high Christology but a high pneumatology as well.
Answer by Dr. Glenn R. Kreider
Dr. Glenn Kreider is a Professor of Theological Studies at Dallas Theological Seminary.