We have learned by sad experience that it is the nature and disposition of almost all men, as soon as they get a little authority, as they suppose, they will immediately begin to exercise unrighteous dominion.
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

COMMENTARY

It is the nature of almost all men, as soon as they get a little authority, to exercise unrighteous dominion
It has been said that one of the best ways to really know a person is to see how they treat their inferiors. When they are in a position of power (whether it be a boss over their employees, a parent over their children, or a pet-owner over their pets) how do they behave towards them?
I was the middle child growing up, and there was definitely a difference between how I interacted with my older siblings and how I treated my younger ones. I felt subservient to my older siblings, and I would try to please them so that they would include me in their games. Meanwhile I felt superior to my younger siblings, and to them I’m afraid I felt the same tendency described in this verse: “to exercise unrighteous dominion.”

No power or influence can or ought to be maintained by virtue of the priesthood
Primarily this dominion took the form of “you should do what I say because I have authority.” Not priesthood authority in this particular case, just an “I’m older” authority. I felt that I was entitled to their obedience because I was bigger than they, and I was not okay if they challenged that belief.

Only by persuasion, by long-suffering, by gentleness and meekness, and by love unfeigned, by kindness, and pure knowledge
Of course my younger siblings did not care for this arrangement. And who could blame them? I didn’t want to be lorded over by my older siblings in that way, and neither did they didn’t want to be lorded over by me.
We all wanted older siblings who earned our respect. Siblings who didn’t take our obedience for granted, but who put in the time to care about us, help us, and play with us. When an older sibling did that, then they could ask a favor and easily receive.