Note: Full blog series can be found here.
For whatever set of reasons, there is a widespread belief out there (internet, popular books) that the New Testament canon was decided at the Council of Nicea in 325 AD—under the conspiratorial influence of Constantine. The fact that this claim was made in Dan Brown’s best-seller The Da Vinci Code shows how widespread it really is. Brown did not make up this belief; he simply used it in his book.
The problem with this belief, however, is that it is patently false. The Council of Nicea had nothing to do with the formation of the New Testament canon (nor did Constantine). Nicea was concerned with how Christians should articulate their beliefs about the divinity of Jesus. Thus it was the birthplace of the Nicean creed.
When people discover that Nicea did not decide the canon, the follow up question is usually, “Which council did decide the canon?” Surely we could not have a canon without some sort of authoritative, official act of the church by which it was decided. Surely we have a canon because some group of men somewhere voted on it. Right?
This whole line of reasoning reveals a fundamental assumption about the New Testament canon that needs to be corrected, namely that it was (or had to be) decided by a church council. The fact of the matter is that when we look into early church history there is no such council. Sure, there are regional church councils that made declarations about the canon (Laodicea, Hippo, Carthage). But these regional councils did not just “pick” books they happened to like, but affirmed the books they believed had functioned as foundational documents for the Christian faith. In other words, these councils were declaring the way things had been, not the way they wanted them to be.
Thus, these councils did not create, authorize, or determine the canon. They simply were part of the process of recognizing a canon that was already there.
This raises an important fact about the New Testament canon that every Christian should know. The shape of our New Testament canon was not determined by a vote or by a council, but by a broad and ancient consensus. Here we can agree with Bart Ehrman, “The canon of the New Testament was ratified by widespread consensus rather than by official proclamation.”
This historical reality is a good reminder that the canon is not just a man-made construct. It was not the result of a power play brokered by rich cultural elites in some smoke filled room. It was the result of many years of God’s people reading, using, and responding to these books.
The same was true for the Old Testament canon. Jesus himself used and cited the Old Testament writings with no indication anywhere that there was uncertainty about which books belonged. Indeed, he held his audience accountable for knowing these books. But, in all of this, there was no Old Testament church council that officially picked them (not even Jamnia). They too were the result of ancient and widespread consensus.
In the end, we can certainly acknowledge that humans played a role in the canonical process. But, not the role that is so commonly attributed to them. Humans did not determine the canon, they responded to it. In this sense, we can say that the canon really chose itself.
 Lost Christianities, 231.