Faulty history lesson that was taught you. If you go back in history, you will see that what is now the NT was being cited verbally and what is written by the early Church (pre-Catholic era). These citations were deemed authoritative by church leaders.
What does that prove?
Let me place this into a modern illustration: Let's say that across America, I am a professor of psychology. Let's say that across America, psych professors left and right spout some major field research-based doctrine from certain sources; and that you find this on just about every campus psych dept (same authoritative sources for what they teach).
Now if some psych professional asso. finally comes along, having recognized this pattern, and gives it some official footing/status as the new standard for licensed folks everywhere, all it's done is to affirm and confirm what is already standard fare on college campuses. Even if you could point to some smaller group of association wonks who incorporated this newly formulated statement, and date it for me, you're missing the point about what has already been authoritatively taught at both the grassroots (& up)! Now if I tell you that this campus doctrine has been well-established (and not uprooted or replaced) for 300+ years!!! Well, that would be even more amazing that something has been that stable as a staple.
So stop spouting off such nonsense. You can effectively put together the NT from all kinds of pre-council sources multiple times over. Why? Because being closer to the original sources, they could generationally trust what weight was given to these sources.
Here's a parable:
Imagine the year is 2150. Fundamentalist break-off groups of Mormonism; internal conflict leading to new Mormon sects; Evangelical wingnuts from FReeperland; + just plain ole secularism is taking its toll on the LDS church. It leads to the forthcoming LDS prophet to call for a new Special General Conference to reiterate what general authorities of old have recognized for years: That the Bible, the Book of Mormon, the D&C, and the PoGP are LDS standard works and should be followed as the Word of God.
Fast-forward then to the era between 3650-3800. One of the more zealous break-off groups of Mormonism has been contending to be the "Real restoration" church--even tho the LDS prophets have labeled them to be "counterfeit." One of the many arguments used by this "Even Later Latter-day" group is that back in 2150 when the LDS prophet called for a Special General Conference in Salt Lake City, well "we all know" that one of the people involved in providing hospitality and civil leadership of the conference was a certain Mayor of Salt Lake City who was a gentile. As such, "we all know" how much "pagan" influence "Gentiles" could wield upon Zion.
Moreover, the abundance of more formalized confirmations of the Standard Works written prior to 2150 have disappeared and can't be located.
And so the "Even Later Latter-day Saints" then continually take aim upon the 2150 Special General Conference statement--to the full exclusion of anything said less formally prior to that by leaders everywhere.
You know the 300+ years between the authorship of many of the NT books (which are authoritatively cited by LDS authorities to this day; which are authoritatively distributed by SLC even in meda ads today, etc) and the councils that Mormons love to hate is a long time for informal recognition to already be well-established. (Think of it; we're only 177 years beyond the BoM)
In my article, I forgot to mention (when I listed all the good atributes of the LDS Church) - I forgot to list the availability of the LDS Family History Centers around the world where anyone is welcome to research their family tree/heritage for free - no string attached. Millions of people have been able to use these resources to complete their family trees.
Many African Americans have been able to trace their ancestry back to plantations and some can trace back further to the slave ship trade. I have read about many successful endeavors in this regard.
It is a wonderful service that the Church provides and I am very proud to mention it here.