There are certain attitudes that provide best practices of sorts for teaching truth. They may surprise you and they may seem to have nothing to do with teaching truth, but they are nonetheless vital.
Be prepared to learn something
When you teach via the spirit of truth, you will always learn something new:
17 Verily I say unto you, he that is ordained of me and sent forth to preach the word of truth by the Comforter, in the Spirit of truth, doth he preach it by the Spirit of truth or some other way?
18 And if it be by some other way it is not of God.
19 And again, he that receiveth the word of truth, doth he receive it by the Spirit of truth or some other way?
20 If it be some other way it is not of God.
21 Therefore, why is it that ye cannot understand and know, that he that receiveth the word by the Spirit of truth receiveth it as it is preached by the Spirit of truth?
22 Wherefore, he that preacheth and he that receiveth, understand one another, and both are edified and rejoice together.
23 And that which doth not edify is not of God, and is darkness. (D&C 50)
For this and other reasons, you should always be prepared to learn something, even while and perhaps especially while in the act of teaching others.
The first key in teaching others is to remember that everything you know is incorrect or incomplete. Every time you seek to teach another, realize that they might actually teach you. A teacher must be exceedingly meek to discern and to learn a lesson from the pupil. A tremendous test of meekness is the attitude one has when interacting with those they assume know less than them.
The prideful assume that any precept that conflicts with their current understanding must be false. They judge truth based on what they already know rather than objectively evaluating it.
The meek, on the other hand, recognize that anyone can teach them something. They assume anything said might be true, and are open to the possibility that they may be wrong. Their current knowledge paradigm is always on the altar.
God said, “All truth is independent in that sphere in which God has placed it.” (D&C 93:30) Two people can testify of competing truths and both be right, because truth is contextual on awareness, and everyone’s awareness is different. The Spirit can reveal something that is true in your “sphere” of understanding, but to someone who has attained to a different “sphere,” or a higher degree of knowledge, it would be false.
This concept is hard for some to accept, but consider a decimal point number as an analogy. Additional digits of precision are true, as are fewer digits of precision. However, to the engineer possessing ten digits’ precision, the decimal of two digits’ precision is less true, and for some applications, downright wrong. Just as one could add digits of precision infinitely, God’s truth never ceases.
Because the degree of glory we enjoy in life is dictated by the degree of God's law that we live, we should always be willing and eager to receive further light and truth in order to expand and clarify the law we currently have. This will likely cause us to change what we are doing. To facilitate this process, we should always be willing to ask questions to further our understanding of answers we have already received—like a child.
We should never judge someone who sincerely and fully believes that their actions are in accordance with God’s word when we have received a different answer to the same question, knowing that it is very possible that they have progressed past us in knowledge. Instead, we should do as Nephi did when presented with his father’s strange claims of having a vision that contradicted Nephi’s understanding: we should pray and ask God. Even if we are not prepared for the answer, God will mobilize the necessary experiences in our life to bring us to the point where we can receive the same knowledge.
Seek to serve
The world believes that the purpose of having more of anything is to be more capable of controlling others:
42 But Jesus called them to him, and saith unto them, Ye know that they which are accounted to rule over the Gentiles exercise lordship over them; and their great ones exercise authority upon them.
43 But so shall it not be among you: but whosoever will be great among you, shall be your minister:
44 And whosoever of you will be the chiefest, shall be servant of all.
45 For even the Son of man came not to be ministered unto, but to minister, and to give his life a ransom for many. (Mark 10)
The truth is that more truth is good for only one thing: more adequately serving others.
God, seeing he was superior, did and does what he does to provide a pathway for others to obtain the same:
God himself, finding he was in the midst of spirits and glory, because he was more intelligent, saw proper to institute laws whereby the rest could have a privilege to advance like himself....He has power to institute laws to instruct the weaker intelligences, that they may be exalted with Himself, so that they might have one glory upon another, and all that knowledge, power, glory, and intelligence, which is requisite in order to save them in the world of spirits. (“Teachings of the Prophet Joseph Smith,” p. 354).
The Lord ordained those with more light and truth to do the same:
22 Now the Lord had shown unto me, Abraham, the intelligences that were organized before the world was; and among all these there were many of the noble and great ones;
23 And God saw these souls that they were good, and he stood in the midst of them, and he said: These I will make my rulers; for he stood among those that were spirits, and he saw that they were good; and he said unto me: Abraham, thou art one of them; thou wast chosen before thou wast born.
24 And there stood one among them that was like unto God, and he said unto those who were with him: We will go down, for there is space there, and we will take of these materials, and we will make an earth whereon these may dwell;
25 And we will prove them herewith, to see if they will do all things whatsoever the Lord their God shall command them;
26 And they who keep their first estate shall be added upon; and they who keep not their first estate shall not have glory in the same kingdom with those who keep their first estate; and they who keep their second estate shall have glory added upon their heads for ever and ever. (Abraham 3)
There is nothing about being better that is desirable to a carnal mind. From a carnal mindset, it is more enjoyable in every way to be mediocre. The only motivation for being better is love of God and love of your fellowman.
Being “great and noble” is not a joyful thing. It is a burden. It doesn't get you a sports car and a trophy spouse. It gets you the knowledge of why these things are not actually desirable.
Truth gets you more opportunities to suffer without recognition for the benefit of others who do not appreciate you. All who will be better will be undesirable to their fellowmen. They will be despised and rejected. They will be full of sorrow. They will suffer for the sins of others. They will be wounded by others. They will be oppressed and afflicted. In spite of all this, no one will listen to them, and they will be comforted only by the knowledge that they had done all they could.
Holding higher truth is not something to be envied in the lens of the world. To be “great and noble” is to be:
...stoned, sawn asunder, tempted, slain with the sword, and [wander] about in sheep skins and goat skins, being destitute, afflicted, tormented...[To wander] in deserts and in mountains, and hid in dens, and caves of the earth; (TPJS p. 32)
Anyone can give a person what they want. Only a real friend will give you what you need, whether or not you are wise enough to know it.
You are responsible to teach what you know
You are nothing special. But God is special, and those who seek him with all their heart will be made capable of having an immeasurable impact through obtaining and disseminating his light:
Yea, he that repenteth and exerciseth faith, and bringeth forth good works, and prayeth continually without ceasing—unto such it is given to know the mysteries of God; yea, unto such it shall be given to reveal things which never have been revealed; yea, and it shall be given unto such to bring thousands of souls to repentance, even as it has been given unto us to bring these our brethren to repentance. (Alma 26:22)
Note how the preceding promise is conditioned only on the individual’s adherence to truth and their application of faith.
God calls upon the weak things of this earth to thrash those who think they are mighty. That is the pattern in scripture. Whether it is stammering Moses, or second-string priest Ezekiel, it seems that he has a ready supply of those weak enough to listen to him.
God is able to do his work. He doesn’t need you, but he does need someone , and it may as well be you. Other people require the truth that you will acquire, assimilate, and disseminate. To the righteous, you can offer light and truth at a faster pace than they could acquire on their own. In far less time, you can convey what took you perhaps a lifetime to learn. To the unrighteous, you can offer—through your intercession—another opportunity for them to learn what they could have on their own if they were obedient and/or diligent.
Without the Lord’s condescending sacrifice, we could not obtain the light he offers us. To a much smaller but equally critical degree, your obtaining light depends on the condescension of others. You can’t be like the Lord without doing the things he did and does. You can, through your heed and diligence, obtain more than others. Then you can give it away through your condescension, supplying more to others than they were capable of obtaining by themselves. This is exactly what God did and does, and it is the whole purpose of creation. This is how you become a “savior on mount Zion” (see Obadiah 1:21).
You have a responsibility to obtain all the light you can, and to share it with others:
What I tell you in darkness, that speak ye in light: and what ye hear in the ear, that preach ye upon the housetops. (Matthew 10:27)
No man, when he hath lighted a candle, putteth it in a secret place, neither under a bushel, but on a candlestick, that they which come in may see the light. (Luke 11:33)
...it becometh every man who hath been warned to warn his neighbor. (D&C 88:81)
To the degree you do this, you will become a savior on mount Zion. To the extent that you do not, you will decrease the joy you have in this life and hereafter:
Whosoever therefore shall break one of these least commandments, and shall teach men so, he shall be called the least in the kingdom of heaven: but whosoever shall do and teach them, the same shall be called great in the kingdom of heaven. (Matthew 5:19)
When we are willing to share what we learn, the Lord gives us more:
For unto every one that hath shall be given, and he shall have abundance: but from him that hath not shall be taken away even that which he hath. (Matthew 25:29)
Those who are willing to share what they learn will find God giving them great treasures of specific wisdom just in time for them to share it with others who desperately need it.
If you don't also teach others what God has taught you, even perfect obedience to those instructions will not save you. If you do not obtain light and share it with others, you will be held responsible:
When I say unto the wicked, Thou shalt surely die; and thou givest him not warning, nor speakest to warn the wicked from his wicked way, to save his life; the same wicked man shall die in his iniquity; but his blood will I require at thine hand. (Ezekiel 3:18)
Contention
God has commanded us not to contend with each other:
For verily, verily I say unto you, he that hath the spirit of contention is not of me, but is of the devil, who is the father of contention, and he stirreth up the hearts of men to contend with anger, one with another. (3 Nephi 11:29)
Yet, not all argument is contention. The word “argue” sometimes connotes anger and disrespect, and not just in modern context. Lehi explained to Laman and Lemuel that they were incorrect in assuming that Nephi's arguments towards them were motivated by anger:
25 And I exceedingly fear and tremble because of you, lest he shall suffer again; for behold, ye have accused him that he sought power and authority over you; but I know that he hath not sought for power nor authority over you, but he hath sought the glory of God, and your own eternal welfare.
26 And ye have murmured because he hath been plain unto you. Ye say that he hath used sharpness; ye say that he hath been angry with you; but behold, his sharpness was the sharpness of the power of the word of God, which was in him; and that which ye call anger was the truth, according to that which is in God, which he could not restrain, manifesting boldly concerning your iniquities.
27 And it must needs be that the power of God must be with him, even unto his commanding you that ye must obey. But behold, it was not he, but it was the Spirit of the Lord which was in him, which opened his mouth to utterance that he could not shut it. (2 Nephi 1)
Arguments, then, are not contentious by definition, but only when they are motivated by anger. Even here, we have to separate the subtle difference between anger and “sharpness.” Arguing truth for the purpose of persuasion can include sharpness (see D&C 121:43). In fact, Jesus frequently employed sharpness. In one typical example, he said:
39 And the Lord said unto him, Now do ye Pharisees make clean the outside of the cup and the platter; but your inward part is full of ravening and wickedness.
40 Ye fools, did not he that made that which is without make that which is within also?
41 But rather give alms of such things as ye have; and, behold, all things are clean unto you.
42 But woe unto you, Pharisees! for ye tithe mint and rue and all manner of herbs, and pass over judgment and the love of God: these ought ye to have done, and not to leave the other undone.
43 Woe unto you, Pharisees! for ye love the uppermost seats in the synagogues, and greetings in the markets.
44 Woe unto you, scribes and Pharisees, hypocrites! for ye are as graves which appear not, and the men that walk over them are not aware of them.
45 Then answered one of the lawyers, and said unto him, Master, thus saying thou reproachest us also.
46 And he said, Woe unto you also, ye lawyers! for ye lade men with burdens grievous to be borne, and ye yourselves touch not the burdens with one of your fingers.
47 Woe unto you! for ye build the sepulchres of the prophets, and your fathers killed them.
48 Truly ye bear witness that ye allow the deeds of your fathers: for they indeed killed them, and ye build their sepulchres. (Luke 11)
How would you react if someone called you a fool, full of wickedness, a hypocrite, and a murderer? Would you consider that contention? Yet, Jesus’ example shows it is not. While it is true that Jesus was gentle with the meek, he was also very sharp with the prideful. Joseph Smith said:
I have not the least idea, if Christ should come to the earth and preach such rough things as He preached to the Jews, but that this generation would reject Him for being so rough. (History of the Church, 5:423)
Jesus is the perfect example to follow. You can't emulate Jesus without arguing and, at times, with sharpness. Sharpness is often the only way to crack through false tradition, an ideological film that is almost always based on an inherited position (by definition, one not based on reasoning or evidences, but an emotive connection). It is very difficult to reason with someone who is arguing from an emotive position.
The definition of “argue” is “to give reasons or cite evidence in support of an idea, action, or theory, typically with the aim of persuading others to share one's view.” When argument is used in the literal sense of the word, the intrinsic motivation will always be persuasion. Argue is the best word to describe how one persuades: producing evidence; reasoning. In contrast, to contend means to strive in order to prove one's position is correct; to defend one's position in order to preserve it, or to oppose. All of these senses have at their heart the intent to remain in one's former position— not, as in the case of argument or debate, to seek out truth, even if it means letting go of one's former position. Contention, then, is not the presence of argument, but the lack thereof, where an individual refuses to give or receive reasons supporting a position.
Contention is about who is right, whereas debate is about what is right. Two persons who are unwilling to change their current position are unable to argue—unable to present evidence to determine what is right. They must take turns asserting who is right. They can only contend with one another. Contention is enmity: the state or feeling of being actively opposed or hostile to someone or something. It is a feeling, not a position informed by reasoning or evidences. It is a non-neutral, non-objective, emotional, irrational practice. It is a reaction against a position rather than a defense against the evidences or reasons behind that position.
If you want to teach truth, you cannot have a contentious attitude.
Demonstrating fruits
The Lord described his ministry by saying:
18 The Spirit of the Lord is upon me, because he hath anointed me to preach the gospel to the poor; he hath sent me to heal the brokenhearted, to preach deliverance to the captives, and recovering of sight to the blind, to set at liberty them that are bruised,
19 To preach the acceptable year of the Lord. (Luke 4)
The Savior provided the following evidence to John the Baptist when asked if he was the Christ:
Go your way, and tell John what things ye have seen and heard; how that the blind see, the lame walk, the lepers are cleansed, the deaf hear, the dead are raised, to the poor the gospel is preached. (Luke 7:22)
Some disciples recognized Jesus’ command over the elements:
And he said unto them, Where is your faith? And they being afraid wondered, saying one to another, What manner of man is this! for he commandeth even the winds and water, and they obey him. (Luke 8:25)
The Samaritan woman recognized Jesus as a source of light because of his supernatural knowledge of details from her past: “Come, see a man, which told me all things that ever I did: is not this the Christ?” (John 4:29)
In the midst of indescribably harrowing trials, Jesus looked down from the cross at his suffering mother and asked John to take care of her, and comforted the scared but repentant thief who was also being crucified.
Jesus demonstrated fruits that indicated he had greater light and truth: He provided instruction and wisdom to alleviate the condition of the poor, the broken, the ignorant, and the incorrect. He commanded the physical world to a greater extent than standard knowledge allows. He loved those who did not deserve love, and he exercised extreme compassion while in the midst of incomparable suffering.
To the extent that you have obtained Jesus’ light, you will do Jesus’ works.