That is an argument from the conclusion. One needs to think about what they were thinking and doing in the 4th century, when this was undecided.
Consensus is no more than man’s stamp of approval on what God has already done and declared but does not validate Scripture, which is inherently Scripture without the validation of man.
Where and how did God declare The Epistle of James, among others, to be Scripture? Martin Luther disagreed with God on this.
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>> “One needs to think about what they were thinking and doing in the 4th century, when this was undecided.” <<
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It was undecided only for the unbelievers that founded the RCC at that time.
Three centuries earlier, the followers of the Way of Yeshua were well aware that all they needed defined was the Tanakh that Yeshua was so good as to affirm for them.
No one with that level of authority has come along since, so it appears that questions WRT the NT writings will remain a matter between the believer and the Holy Spirit.
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