Nicaea didn’t choose the books of the Bible. So who did?

No council sat down and chose the Bible. The 27 books of the New Testament emerged through about three centuries of use, argument and gradual agreement among Christian communities. The Council of Nicaea in 325, often credited with the decision, left no record of ruling on the canon at all. [1]

Around 140, Marcion of Sinope circulated a fixed list of his own: an edited Gospel of Luke and ten letters of Paul, with the Hebrew scriptures rejected entirely. [1]

Many historians think this pushed other Christians to define their own collection. Others argue that the four-Gospel collection was already forming and that Marcion mattered less than the story suggests.

The Muratorian fragment lists most of the New Testament books. It is usually dated to the late second century, though some scholars place it in the fourth. [2]

In the early fourth century, Eusebius sorted Christian writings into accepted, disputed and rejected. James, Jude, 2 Peter, and 2 and 3 John were still in his disputed group. [3]

In his Easter letter of 367, Athanasius of Alexandria listed exactly the 27 books used today. It is the earliest surviving list to do so. [4]

Regional councils at Hippo in 393 and Carthage in 397 later endorsed the same list. [1]

My own take: the Nicaea story survives because a single dramatic vote is easier to remember than a slow consensus. Novels like The Da Vinci Code put a version of it in front of millions of readers.