I started the class by telling everyone that I really struggled to prepare this lesson, because I had felt some impressions about structuring it around something that might be seen as controversial by some members - but which I believe is probably the best example possible of why it is important to focus on pure doctrine, why it is important not to stray into the purely / highly speculative and how we should approach understanding anything in relation to truth and error.
We then read the first scriptural passage in the truth vs. error lesson outline - John 8:31-32. I read verses 25-29 to lay the groundwork to understand the context, focusing on the fact that Jesus started by talking about doing the will of the Father and then addressing 31-32 exclusively to those who "believed on him" - a subset of those to whom he had been teaching originally. Thus, 31-32 was said to believers - those who accepted his statement that he was representing the Father and were looking for a practical answer to what they should do with that belief.
John 31-32 says:
If ye continue in my word, then are ye my disciples indeed; and ye shall know the truth, and the truth shall make you free.
We talked about the most important words in that passage: "continue", "truth" and "free". We discussed the idea that "continuing" means nothing more than "not stopping" - but, in Mormon theology, it also carries connotations of "progress" (which includes an inherent aspect of "growth and change"). It is that continuation of growth and change that, eventually, creates a "new creature in Christ" that is free - specifically from the limitations, restrictions, bonds, etc. that existed prior to "know(ing) the truth". Thus, the ultimate end of knowing truth from error is freedom from ignorance and all of its mortal applications.
We then discussed D&C 9:7-8 (all of 7 and the first sentence of 8), after discussing the context of the section, which reads:
Behold, you have not understood; you have supposed that I would give it unto you, when you took no thought save it was to ask me. But, behold, I say unto you, that you must study it out in your mind.
I mentioned to them how often we talk in the Church about the confirmation of the Holy Ghost in terms of how we feel (our spiritual/emotional/heart experience) but how little we tend to mention our minds as part of the testimony toolbox, if you will. I explained that I don't take anything as "pure doctrine" unless it speaks compellingly to BOTH my heart AND my mind - that there are things that resonate with my heart or mind but not with the other - that I try not to rely on only one of those things in constructing what I believe - that I only accept it as part of my own faith if I like how I feel and think about it. I told them that when there is a disconnect between the two, I try to dig deeper into the disconnected aspect and understand why the disconnect exists by looking more closely at it - not by ignoring it. I mentioned that problems can occur when either the heart or mind is allowed to dominate - that the heart alone can lead to emotional conclusions that aren't true, while the mind alone can lead to an intellectualism that denies feelings and can allow someone to lose sight of morality and humanity.
Focusing on "pure doctrine" is important in this process, because it explicitly is when we leave pure doctrine and move into speculation that things get all kinds of messed up and we become enslaved (not free) by our mistaken understandings.
I told them that this was the point over which I agonized in the preparation of the lesson. I wanted to use a real example of something that was not "pure doctrine" but which mutated into being seen as pure doctrine due to the mortal inability to distinguish between truth and error and the similar mortal tendency to hold on to false traditions and teachings. The best example I know of this is the Priesthood ban, so I mentioned the Joseph Smith Papers Project and the explanations of various things that the Church has published recently on lds.org in the Gospel Topics section.
First, I asked the students who was allowed to be baptized when the Church was established in 1830. They all answered that anyone of age could be baptized, regardless of sex, race, ethnicity, etc. I asked who could be ordained to an office in the Priesthood and attend the temple. They said all worthy members could attend the temple and all worthy men could be ordained, except for black men. (My daughter wasn't allowed to answer, since we have talked about all of this in the past.) I told them that answer was wrong - that, originally, there were no restrictions based on race and that a handful of black men had been ordained to the Melchizedek Priesthood and endowed in the temple. I then summarized the lds.org explanation and talked about the prevailing "philosophies of men" and how they worked their way into our teachings - and how uniquely Mormon justifications arose when people tried to explain why the ban was in place. I mentioned the belief in a curse of Cain, the idea that the Church couldn't ordain black men in the political environment of the time, the belief that black men and women had been less valiant in the pre-existence / fence-sitters, etc. - and how those justifications allowed white people to think they were better than black people. I explained that every reference we have in our scriptures that might seem to support those conclusions to any degree occurs PRIOR to the life and death of Jesus - and that there are verses in the New Testament and the Book of Mormon that state, clearly, that, as of that time, ALL people were alike to God - including both black and white, explicitly.
We talked about how we all tend to explain rules, policies, commandments, counsel, etc. in order to justify them - in school, at work, in church and everywhere else. I mentioned Elder McConkie's statement in 1978 after OD2 and the rescinding of the ban about forgetting everything he and anyone else had said about the reason(s) for the ban - that they had spoken with limited light and knowledge and now had increased light and knowledge that repudiated everything they had said in the past. I stressed the importance of not holding so tightly to anything that they might lose the ability to let go when further light and knowledge appears, as I'm sure will happen in their lifetimes.
In the context of the lesson topics, we talked about how the entire thing might have been avoided if the early saints (including Pres. Young) could have let go of their bias against inter-racial marriage, focused solely on "pure doctrine" and been open to new understanding of truth and error. I told them that they never have to accept or believe something FULLY, without question or concern, simply because it is taught in the Church - that, ultimately, they have to receive confirmation in their hearts and minds about anything and, if necessary, hold onto hope and faith that what they can't accept or believe fully at the moment will change in the future - either the thing they can't accept or their personal understanding of it.