In ”Lost Christianities: The Battles for Scripture and the Faiths We Never Knew”, Bart Ehrman claims that early Christianity was so fargmented that, essentially, there were possibly as many forms of Christianity as there were people.1
This page heavily utilizes content from The Heresy of Orthodoxy by Andreas J. Kostenberger and Michael J. Kruger.
In contrast to Ehrman’s claims, the reality, based on the historical evidence we have, is this:
Adolf von Harnack suggested that Hellenism so influenced the post-New Testament church that the original understanding of the gospel message was lost.2 Essentially, the post-New Testament church incorporated aspects of the surrounding culture and added layers to the gospel, which resulted in a fundamentally different “gospel” from the original gospel.
Christianity started with Jesus and the apostles, but it continued to develop and evolve throughout the centuries. Because of this, fourth century Christianity was fundamentally different from the original Christianity.3
This is the subject of Ehrman’s book. He argues that there were many early “Christianities” and that the “orthodox Christianity” we have today was simply the version of Christianity that won out among the others.
John Behr argued that the theology of the New Testament continued in an uninterrupted manner throughout the time of the church fathers and the Apologists (early Christian writers from c. AD 120–220 who defended the Christian faith and argued for it to outsiders) and was solidified in the ecumenical church councils (Nicaea, AD 325, and subsequent councils in AD 381, 431, 451, 553, 680–681, and 787).
According to Behr, post-New Testament orthodox Christians clarified and explained the theology of the New Testament without changing it, and the creeds produced by the church councils accurately reflect the theology of the New Testament.4
This is the view we will be defending, and it is the view that most accurately describes the evidence we have from the first two centuries of the church.
Post-New Testament writers refer to something called the “Rule of Faith,” or, alternatively, the Rule of Piety, Ecclesiastical Rule, Rule of the Church, Evangelical Rule, Rule of the Gospel, Rule of Tradition, Sound Rule, Full Faith, Analogy of Faith, Law of Faith, Canon of the Truth, Canon of the Church, and Preaching of the Church.
The earliest reference to this Rule is in ”1 Clement” (c. AD 96):
Wherefore let us forsake idle and vain thoughts; and let us conform to the glorious and venerable ”’rule which hath been handed down to us”’;
1 Clement 7:2
The Rule is referenced by almost all of the orthodox writings from the patristic era from various geographical areas:
The exact definition of the Rule is never explicitly stated by the church fathers, but there is relative agreement among scholars that it was a basic statement about the church’s common faith.
One of the primary theological foundations for the New Testament writers was Jesus’ death, burial, and resurrection for the forgiveness of sins. The Rule almost certainly includes this core belief.
So, from essentially the beginning of the post-New Testament era, a geographically diverse group of Christian writers wrote about a “Rule of Faith,” or a unified theological standard.
The church fathers believed the Rule—the unified theological standard—should be “handed down.” They did seek to create anything new, but rather to explain more fully that which already existed.
In this order, and by this succession, the ecclesiastical tradition from the apostles, and the preaching of the truth, ”’have come down to us”’. And this is most abundant proof that there is one and the same vivifying faith, which has been preserved in the Church from the apostles until now, and ”’handed down”’ in truth.11
Irenaeus, ”Against Heresies”, 3.3.3.
The Apostles ”’received the Gospel for us from the Lord Jesus Christ”’; Jesus Christ was sent forth from God. So then Christ is from God, and the Apostles are from Christ. Both therefore came of the will of God in the appointed order. ”’Having therefore received a charge”’, and having been fully assured through the resurrection of our Lord Jesus Christ and confirmed in the word of God with full assurance of the Holy Ghost, they went forth with the glad tidings that the kingdom of God should come. So preaching everywhere in country and town, they appointed their firstfruits, when they had proved them by the Spirit, to be bishops and deacons unto them that should believe. ”’And this they did in no new fashion; for indeed it had been written concerning bishops and deacons from very ancient times”’; for thus saith the scripture in a certain place, I will appoint their bishops in righteousness and their deacons in faith.
1 Clement 42:1-5 (c. AD 96)
… I advise you, be ye zealous to do all things in godly concord, the bishop presiding after the likeness of God and the presbyters after the likeness of the council of the Apostles
…
Do your diligence therefore that ye be confirmed in the ordinances of the Lord and of the Apostles…
Ignatius, ”Ignatius to the Magnesians”, 6:1, 13:1.
But if any one preach the Jewish law unto you, listen not to him. For it is better to hearken to Christian doctrine from a man who has been circumcised, than to Judaism from one uncircumcised. But ”’if either of such persons do not speak concerning Jesus Christ”’, they are in my judgment but as monuments and sepulchres of the dead, upon which are written only the names of men.
Ignatius, ”The Epistle of Ignatius to the Philadelphians”, 6.
The church fathers believed the Rule originated in the Old Testament with the prophets, and their message continued with the apostles, who, like the prophets, were sent from God.12
For these words have neither been prepared by me, nor embellished by the art of man; but David sung them, Isaiah preached them, Zechariah proclaimed them, and Moses wrote them.
Justin Martyr, ”Dialogue with Trypho”, 29.
but the Jews and Samaritans, having the word of God delivered to them by the prophets, and always expecting the Christ, did not recognise Him when He came, except some few, of whom the Spirit of prophecy by Isaiah had predicted that they should be saved.
Justin Martyr, ”The First Apology”, 53.
Moses received them, but they themselves were not found worthy. Buthow did we receive them? Mark this. Moses received them being aservant, but the Lord himself gave them to us to be the people of Hisinheritance, having endured patiently for our sakes.
The Epistle of Barnabas 14:4
Second-century sects sought to sever the gospel message from the Old Testament, and they taught that there was new, secret knowledge about Jesus that overrode any knowledge that came from the past.
In contrast, the church fathers saw their message, which they called the Rule, as something that originated in the Old Testament, was fulfilled in Christ, and was taught by the apostles. The church fathers saw their role as the preservers and propagators of this same message that existed long ago.
The church fathers guarded and propagated the theological contents of the Rule—or, in other words, the core gospel message—so that they eventually made their way into the creeds of the third and fourth century.
Gerald Bray makes a strong argument that every doctrine in the creeds of the third and fourth century is found in the New Testament and was propagated through the church fathers.13
D.A. Carson writes, “[While it may be erroneous] to read… fourth-century orthodoxy back into the New Testament… it is equally wrong to suggest that there are few ties between fourth-century orthodoxy and the New Testament.”14
Although the creeds do not introduce any new theology than what exists in the New Testament, the specific terminology and phrasing used in the creeds are sometimes different than what the writers of the New Testament used. For example, the Bible never uses the specific word “Trinity,” but the doctrine of the Trinity is clearly taught throughout the Bible (for example, see Matthew 28:19 and 1 Peter 1:2).