Joseph Smith co-wrote a letter from Liberty Jail. The entire letter can be found either in the Documentary History of the Church, vol. 3, pp.289 through 305, or in TPJS, pp.129 through 148. The letter is where D&C Sections 121, 122 and 123 came from.
When you read the entire letter you can see how our scriptural excerpts skip about and leave out paragraphs. It jumps around from one disconnected thought to another. The impression you get from the D&C sections leads you to believe that each verse follows in order.
I leave it to you to track the differences. It is well worth the effort. There is only one matter I would like to call to your attention. Section 121 ends and Section 122 begins in the same thought. In the original letter there was no division between them. They belong together. As presently published, the impression you get is that Section 122 is speaking about Joseph Smith. While it certainly would apply to him, it also applies to you. Here, then, is how this section of the letter was originally composed. Read these words as one thought, and apply that thought to yourself:
No power or influence can or ought to be maintained by virtue of the Priesthood, only by persuasion, by long-suffering, by gentleness and meekness, and by love unfeigned; by kindness, and pure knowledge, which shall greatly enlarge the soul without hypocrisy, and without guile, reproving betimes with sharpness, when moved upon by the Holy Ghost, and then showing forth afterwards an increase of love toward him whom thou hast reproved, lest he esteem thee to be his enemy; that he may know that thy faithfulness is stronger than the chords of death; let thy bowels also be full of charity towards all men, and to the household of faith, and let virtue garnish thy thoughts unceasingly; then shall thy confidence wax strong in the presence of God; and the doctrine of the priesthood shall distill upon thy soul as the dews from heaven. The Holy Ghost shall be thy constant companion, and thy scepter an unchanging scepter of righteousness and truth; and thy dominion shall be an everlasting dominion, and without compulsory means it shall flow unto thee forever and ever. The ends of the earth shall inquire after thy name, and fools shall have thee in derision, and hell shall rage against thee; While the pure in heart, and the wise, and the noble, and the virtuous, shall seek counsel, and authority, and blessings constantly from under thy hand. And thy people shall never be turned against thee by the testimony of traitors. And although their influence shall cast thee into trouble, and into bars and walls, thou shalt be had in honor; and but for a small moment and thy voice shall be more terrible in the midst of thine enemies than the fierce lion, because of thy righteousness; and thy God shall stand by thee forever and ever.
This is how to act as a priest, and also to understand doctrine because you are serving in the way God requires. As a result of living these principles your confidence will grow in the presence of God. This is how you will obtain a scepter of righteousness given you by God.
This describes Joseph. It describes the faith Joseph had and the religion he lived. You live it too. You rise up likewise to gain confidence in the presence of God. If you do, God will stand by you forever and ever and you will no longer need to fear any man.