New Testament Christianity is deeply rooted in God’s revelation of Himself as the Trinity; one and only one God who exists in three coequal and coeternal persons. It is not merely true that Scripture plainly reveals the doctrine of the Trinity. Scripture also shows us that this teaching was central in the life and community of early Christians. This truth permeated their thinking and flowed out into their communication, so that Trinitarian “formulas,” so to speak, are frequently invoked in communicating the works and blessings of God. Take, for instance, the outward expression of repentance and devotion to Christ by which one entered into the Christian community, that of Baptism. Jesus Himself said:

“Go therefore and make disciples of all the nations, baptizing them in the name of the Father and the Son and the Holy Spirit,” (Matthew 28:19).

One could not enter into fellowship with the church without an acknowledgment that they were doing so in the one name and singular authority of the Father, Son, and Spirit. Consider also how they evoked the Trinity in blessing one another, such as in the salutation at the end of Paul’s letter to the Corinthian Church:

“The grace of the Lord Jesus Christ, and the love of God, and the fellowship of the Holy Spirit, be with you all,” (2 Corinthians 13:14).

There are no biblical passages where believers wished the grace of Moses, Elijah, or even the Archangel Michael on one another, nor did they wish one another the fellowship of impersonal forces like the wind or angelic messengers like Gabriel. The grace of the Lord Jesus is a divine Grace. The fellowship of the Holy Spirit is a personal fellowship with one who is equated with God and Christ. This is thoroughly Trinitarian.

The greetings in biblical letters also sometimes expressed this truth, such as the open lines of Peter’s first letter:

“To those who reside as aliens, scattered throughout Pontus, Galatia, Cappadocia, Asia, and Bithynia, who are chosen according to the foreknowledge of God the Father, by the sanctifying work of the Spirit, to obey Jesus Christ and be sprinkled with His blood: May grace and peace be yours in the fullest measure,” (1 Peter 1:1-2).

Not only did Peter greet the brethren in the Father, Son, and Holy Spirit, he expressed the divine work of salvation as the Trinity’s work. The redemption of the saints in the choice of the Father, it is the sanctifying work of the Spirit, it is accomplished in the blood of Christ and is unto obedience to Him. The gospel is a Trinitarian message! Salvation is the work of the Father, Son, and Holy Spirit. Scripture gives expression to this same idea elsewhere. Take, for example, how the author of the Book of Hebrews puts it:

“How much more will the blood of Christ, who through the eternal Spirit offered Himself without blemish to God, cleanse your conscience from dead works to serve the living God? ” (Hebrews 9:14).

And we see a powerful expression of this in Paul’s words to the Ephesians elders in the book of Acts:

“Be on guard for yourselves and for all the flock, among which the Holy Spirit has made you overseers, to shepherd the church of God which He purchased with His own blood,” (Acts 20:28).

It is possible that this verse straightforwardly says that God shed His own blood for the church, which would be a clear testimony to the deity of Christ. Many scholars (even faithful Christian scholars) argue, however, that the Greek here reflects the idea of the “the blood of His own,” rather than, “His own blood.” Therefore, the word “God” here is used specifically of the Father and “His own” would be Jesus Christ. Even if we take it this way, Paul is still expressing the gospel in a thoroughly Trinitarian manner.

Paul also expressed elsewhere that living out the Christian life was equally rooted in the Trinity. Note, as one example, these words from His letter to the church at Ephesus:

“For this reason I bow my knees before the Father, from whom every family in heaven and on earth derives its name, that He would grant you, according to the riches of His glory, to be strengthened with power through His Spirit in the inner man, so that Christ may dwell in your hearts through faith,” (Ephesians 3:14-17).

Jude likewise exhorted in his letter:

“But you, beloved, building yourselves up on your most holy faith, praying in the Holy Spirit, keep yourselves in the love of God, waiting anxiously for the mercy of our Lord Jesus Christ to eternal life,” (Jude 20-21).

Thus, the New Testament writers used Trinitarian language throughout their life and worship. And what was true of the biblical authors was also true of the earliest Christians who received the faith from them. In the Didache, one of the earliest Christian writings outside the New Testament which dates to within the lifetime of the first generation of Christians. Instructing on baptism, it says:

“Baptize into the name of the Father, and of the Son, and of the Holy Spirit, in living water. But if you have no living water, baptize into other water; and if you cannot do so in cold water, do so in warm. But if you have neither, pour out water three times upon the head into the name of the Father and Son and Holy Spirit,” (Didache, Chapter 7).

Likewise, Justin Martyr, a Christian writer from the middle of the second century, records how communion was carried out:

“Then bread and a cup of wine mixed with water are brought to the presiding brother. Taking them, he gives praise and glory to the Father of the universe through the name of the Son and of the Holy Spirit,” (Justin Martyr, First Apology, Chapter 65).

The Didache and the writings of Justin Martyr are, of course, fallible human documents. They also only tell us what Christians were doing in their own respective local areas. Indeed, when one reads both documents thoroughly, there are differences in the way these two churches did things. What is clear, however, is that the ritual life and worship of the early Christians centered on the name, authority and redemptive work of the Father, Son, and Holy Spirit. This truth may have found different outward expressions by various congregations, but we always find it there, and it is always Trinitarian.

We also see the pattern continued in the earliest Christian letters. The epistle from the Christian elders in Rome to the church in Corinth, which they wrote in the latter part of the first century, says:

“For as God lives, and the Lord Jesus Christ lives, and the Holy Spirit, who are the faith and the hope of the elect,” (Clement of Rome, Letter to the Corinthians, Chapter 58).

Notice that the Father, Son, and Holy Spirit are “the faith and hope of the elect.” Powerful words indeed! The letters of Ignatius, the overseer of the Church of Antioch in the earliest decades of the second century, abound in such references. As just one example, note his salutation at the end of his letter to the Magnesians:

“Fare ye well in harmony, ye who have obtained the inseparable Spirit, in Christ Jesus, by the will of God,” (Ignatius, Epistle to the Magnesians, Chapter 15).

Aristides, who lived in Athens in the early second century and was one of the first Christian apologists, wrote:

“For they know God, the Creator and Fashioner of all things through the only-begotten Son and the Holy Spirit; and beside Him they worship no other God,” (Apology of Aristides, Chapter 15)

And also Polycarp, the leader of the Church in Smyrna and an early Christian martyr, prayed on the day of his death:

“Therefore, I also praise You for all things, I bless You, I glorify You, along with the everlasting and heavenly Jesus Christ, Your beloved Son, with whom, to You and the Holy Ghost, be glory both now and to all coming ages. Amen,” (Martyrdom of Polycarp, Chapter 14).¹One early source reporting this prayer reads “in the Holy Spirit” rather than “and the Holy Spirit.” For our purposes here, the point remains the same. Polycarp, while facing death for his faith, evoked the Father, Son, and Holy Spirit in his prayer.

Irenaeus, a major Christian thinker of the later Second century, also continued this practice. Such formulas can be found throughout his work, such as here where He describes the creation of man as a triune work:

“Now God shall be glorified in His handiwork, fitting it so as to be conformable to, and modeled after, His own Son. For by the hands of the Father, that is, by the Son and the Holy Spirit, man, and not [merely] a part of man, was made in the likeness of God,” (Irenaeus, Against Heresies, Book 5, Chapter 6).

When God created the universe and man within it, when he formed it by Himself with His own hands (Isaiah 45:12), that was Father, Son, and Holy Spirit. When God made man in His own image, Irenaeus says He made him, “to be conformable to, and modeled after,” the Son. Creation in general and humanity, in particular, are Trinitarian works. This is what the early Christians expressed.

While the mere use of such formulas does not automatically prove that these early Christians believed Father, Son, and Holy Spirit all to be God, when we consider what they are saying when they evoke these titles together, it is hard to come to any other conclusion. Consider some of the alternatives.

• The Jehovah’s Witnesses say that the Father is Jehovah God, the Son is Michael the Archangel, and the Holy Spirit is merely a description of the supernatural power by which God carries out His mighty works. But why would Christians baptize in the name of God, a mere angel, and a descriptive term for God’s miraculous power?
• Muslims believe that Jesus is only a human prophet and that the “Holy Spirit” is the Angel Gabriel. But do you really think someone would end their letter with the blessing, “The grace of a mere prophet, the love of God, and the fellowship of the Angel Gabriel be with you.”
• Would the early Christians have said that an angel, a prophet, or an impersonal force were the “faith and the hope of the elect,” alongside God Himself? Could one possibly attribute the creation of mankind to a man who had not yet been created? Could anyone take “made in God’s image” to mean “modeled after Michael the Archangel?”

No, this pattern only makes sense in the context of the clear, biblical teaching that the one and only God exists as Father, Son, and Holy Spirit. This wondrous, tri-personal God is at the center of the Christian faith and should be the center of the Christian life.