The problem you have is that 99 percent of what you read must fall into that category, whether you recognise it or not, indeed how can you be sure YOUR version is the false doctrine?.
It is a sad fact that post reformation protestants now have mutually exclusive doctrine on almost every aspect of christian doctrine.
There are several mutually EXCLUSIVE doctrines on
Eucharist
Baptism
Salvation
God Head/Trinity
Pro life or choice
End Times
Clergy/ Succession
LGBT issues
Divorce and remarriage
Role of Church and Authority
What constitutes scripture
Down to arcane matters, like...what happens if a child dies pre baptism?
And many other issues
In short tens of thousands of permutations , only ONE of which can be true.
And they are exclusive. Take the myriad of versions of salvation. Once saved always saved, saved but can lose it, not saved to the end of the journey by grace , or doubly or singly predestined, are alternative. They cannot be simultaneously true - so there are many False doctrines, only one true. Saved by faith. Is baptism essential? The importance of works of charity or of the law....the list goes on.
Viewed through the lens of one denomination, others are seen as "false teaching"
And the obvious truth, supported by history and scripture is that sola scriptura itself is the problem. Which is clearly a false doctrine - amply proven by the fact that scripture says the "pillar of truth is the church" not scripture.. Scripture is not a complete manual of christian life, nor does it claim to be. There are clearly many interpretations as you see above and "somethign else other than scripture" is needed to resolve them. As you see from the list of permutations "asking the holy spirit for guidance" has not helped most who have stated that as the way to resolve differences.
So the question to be asked is how did Jesus tell you what was true teaching.
The answer is he did not give you a book...not surprising, few could read, and even if they could it would be almost two millenia before average person could own a bible.
Jesus gave you apostles and the succession to pass on the truth - the process called "paradosis" - (now translated as tradition, but the colloquial meaning of that in 21st century has lost what it meant back then). That is why apostle paul told you to "stay true to tradition we taught you by word of mouth and letter" - elsewhere - "how can they preach if they are not sent?"
Jesus also specified the authority to resolve arguments of doctrine - the power to bind and loose - given to apostles together (and manifested by decisions of councils including those that formed your new testament centuries on) - and also to successors of Peter, the office of keys to whom he said "tend my flock"
So study what the apostles handed on. See that in the early church fathers writing. Take ignatius to Smyrneans - he and polycarp disciples of john the apostles - clearly stating that a valid eucharist was the body and blood of our lord, and that only a bishop or his appointee could perform it. Or study ignatius, see reference to infant baptism. See augustine quoting the list of popes as scucessors of peter as the authority against donatism, see the doctrine of those who chose your new testament, vociferous on the intercession of Mary And so on.
So of the many versions of eucharist you cannot make up your own meaning from scripture. The truth is the truth and has always been, and it is there in early church fathers.
But coming back to your point, there are those who will regard any other version than their own as false doctrine.
Sola scriptura - the false man made tradition of the reformation - was the father of 10000 schisms. Scripture is truth. But is not enough by itself. The parts that are missing are authority , and tradition (in the real meaning not the contemporary one)
Imagine you are reading a post on CF (Not this one,
), and you start reading some strange stuff, stuff that you have never read in the Bible. It may have a nice sound to it, but it just doesn't seem quite right. It might even be "alluring" or looking like an appealing bait, or appetizer. Then you recognize it. You can almost hear the hiss of the serpent in the Garden of Eden. You know now that this is not the voice of the Spirit, or of Jesus (John 10:27). You could easily just stop reading, and move on to another post, or something else, and that might be the appropriate action for some. But these words on this post that is just not quite right, or no where close to right is still there for others to read.
It reminds me of years ago, while working as a security supervisor at a hotel, of occasionally coming across pornographic magazines left in the hallways. Now I could be tempted to look at them, or I could ignore them, or I could just throw them away. But then others might still find them and fall for/to their destructiveness. As a Christian I developed a plan for finding them in the future. "Find it, fold it, and fling it." Find it, and don't look at the cover and be enticed by that, and then want to see more. NO!!! Fold that magazine in half immediately so as not to see the cover. Then don't just throw it away for someone else to find. Take it to the trash compactor and fling it all the way to the back, and push the button to move it to a place where it will become irretrievable (at least by me and others in the hotel.) Now not everyone has access to a trash compactor, but come up with a similar plan for dealing with your own temptations, something that is practical, workable, and effective.
So when we find posts on this website, posts maybe we don't think we necessarily should REPORT, how should we respond? Argue, debate, teach,... ? I would like to hear from you.