Seems to me Paul saw this occurring in the early church as some were following the teachings of one teacher over another and his word to them in 1 Cor 3 was that they were acting as 'babes in Christ' and were showing how 'worldly' they were in their dissensions. Imo, this human (as Paul put it) approach to becoming the 'true church' has done more harm than good in presenting Christianity to the world. Could it be that we all are remaining as 'babes' as we draw our lines and argue on what is Christian and what is not ? Is there such a thing as flawless fruit inspection ?
I don't know how all these early church teachings differed from one teacher to another and these in 1 Cor 3 would not have access to all the writings as we do after the NT was assembled and I think the warning Paul gave is one to keep in mind. Jesus knows His sheep and they follow Him. Not perfectly, as like sheep we are prone to wander. Nor do any of us understand clearly as we see through a glass darkly.
I think it is easy to use terms like the 'authority of the scriptures' to support our own interpretations as we see them as black and white instructions. But we can't get around the fact that those with opposing understandings of the same scriptures also refer to the 'authority of the scriptures' as they feel lead to believe. Personally, I don't need a local fellowship of believers to agree on anything but the core beliefs in Jesus that brings about salvation. Others believe to fellowship with other followers of Christ we need much more than this. I doubt I will ever 'sign on' to a 'statement of faith' or a 'church covenant' to become a 'member' of any local group of believers. That is, unless I hear better scriptural arguments supporting this need than I have received to date.
Anyway, as history has shown, I would not be surprised that this example of a break off into another stand on what the scriptures really means will someday break off again as is common amongst Anabaptists. Another one to add to the chart of Anabaptist splits. Is it scriptural to use words like 'Covenant' and 'Brethren' in a NT group title ?
Jesus is the one and only Truth. I believe to know Truth is getting to know Him better that will cause us to love one another despite our varied understandings of NT writings. The Truth sets us free from many things.