The troubles in the church are always doctrinal. Someone is trying to introduce something alien. Usually it is called "something new", but as it says in Ecclesiastes 1:9, there is nothing new under the sun.
Typically such alien intrusions are referred to as "error". By that word, people tend to want to communicate that something is wrong. But the word carries with it a connotation of a mistake. When teachers in the modern church try to introduce something contrary to Scriptures and the Confessions, it is not a mistake, a misstep of reason, or a misunderstanding, it is deliberate evil.
The problem is that the field is currently fixated on the idea that the Bible is a work of fiction. Many Bible "experts" would not say it so bluntly. They would talk about traditions, oral and written, about redactors and their work, and such, in a wondrously esoteric technical language, but when it comes down to the final sense, it means that the things the Bible reports probably never happened in real-world history, and that the best one can hope for from the Scriptures is a sense of the religious sensibilities of a previous and primitive people as they wrestled with life and questions of its meaning and purpose.
Even the New Testament is treated to this apriori assumption. Scholars do not believe the individual documents were actually penned by the authors traditionally held to have written them. The events, particularly the miraculous events, are assumed to have never occurred, Jesus is treated as basically unknown and unknowable, and therefore the Jesus of the Bible is a work of pious fiction. Observe the work or the Jesus Seminar as evidence of this attitude.
I hasten to note that there are believing Bible Scholars. They are simply in the minority and have little influence on the course of the discipline. The big thing is still to teach the documentary hypothesis, and the diversity of deities and theologies presented in the text as we have it today, and to deny and ignore rectilinear prophecy. The precise points of the dominant hypotheses being debated is always in flux, but the discipline begins today with the notion that the text is unclear, non-historical in what it reports, and unreliable.
The scholar who absorbs this attitude must fall from the faith, for the source of all of the knowledge and the foundation of their faith is demonstrated by the "science" of their discipline to be fiction, not real, not true in the sense of correlation with reality. To go anywhere in the field and do anything impressive and new, one must adopt the critical approach and attitudes of the discipline. One may know the content of the discipline while rejecting that it is true, but to really do something that moves the discipline, you gotta be a member of the club, a true believer -- not in God, but in the skepticism of the discipline.
The prime mover in this industry of unbelief is, of course, the devil, the father of lies. He would have everyone doubt and disbelieve. Human pride plays a part, for rather than laugh unbelief off the stage, the church cautiously tiptoes around it, tries to curry the favor of the proponents of unbelief, and tries to salvage scraps of truth and knowledge, so-called, from the work of the unbelievers who study the text of God's Word. Something in us yearns for the acceptance and validation of the "experts", even when they are clearly the enemies of our faith. We want to wear the mantle of being "intelligent" when we should be striving to wear the mantle of being faithful.
But the false teachings and the denial of clear truth is not an error, nor should we honor it by giving it that title, it is, more clearly now than ever before, deliberate and despicable evil. Let them stand up and say that they reject the faith, denounce the sounds words, those of our Lord Jesus Christ, and have a new path, and I will respect them as committed errorists, who champion their faith, which is clearly another (see Galatians 1:6-7). Until they do, however, they are quisling, fifth-column traitors, and deliberately and despicably evil, attempting to sneak in error to pollute the truth and lead the unwary to their destruction!
May God ever guard and keep His faithful people from such men and women. It is not error -- it is evil!