From the first through the fourth centuries, local church communities maintained their own list of writings that agreed with apostolic tradition. At first, the lists were significantly different but as time passed they became nearly identical until a final list was selected universally at the end of the fourth century. These 27 books were selected precisely because they were consistently useful to congregations when read within the liturgy.
More than 27 writings from the first century prove to not contradict the apostles’ teaching and local churches in the first and se By the third and even more by the fourth century the lists kept by the various churches grew closer and closer together. As time passed it became more and more clear which writings should be kept in the list and which should be set to the side.cond century used a range of writings.
The main force behind these decisions was the liturgy. The whole purpose of keeping a list of writings that were trusted by the church community was to know what to read at Mass. Copies were extremely expensive and literacy was around 10% so the only use of the writings was in formation of clergy and in reading them in the liturgy. As time went on, local churches identified which writings were really helpful to their congregations. Those writings were kept while those that just weren’t all that useful in the context of the liturgy were more and more sidelined.
That the 27 book in the New Testament proved to be the best suited for the liturgy over hundreds of years is yet another reason Catholics are confident in them.