Bhagavad Gita Verse 22, Chapter 16

etairvimuktaha kaunteya tamodvaaraistribhirnaraha |
aacharatyaatmanaha shreyastato yaati paraam gatim || 22 ||
 
One who is free from these, the three gates of darkness, does good to himself, O Kaunteya, and with that, attains the supreme goal.
 
etaihi : these
vimuktaha : free
kaunteya : O Kaunteya
tamodvaaraihi : gates of darkness
tribhihi : three
naraha : one who
aacharati : does
aatmanaha : himself
shreyaha : good
tataha : with that
yaati : attains
paraam : supreme
gatim : goal
 
Shri Krishna describes the fate of one who has successfully conquered desire, anger and greed, the three gates of tamas or darkness. He says that such a person, from a practical standpoint, puts his life on the right track, he does good to himself. From an absolute standpoint, such a person attains the supreme goal of self realization, of oneness with Ishvara, instead of entrapment in the never ending cycle of birth and death.
 
With this shloka, the message of the entire sixteenth chapter is summarized and concluded. Most of us, given the materialistic nature of the world, are on the path of preyas, the pleasant, the path of continuous satisfaction of selfish desires. Shri Krishna urges us to slowly tune down the three devilish qualities of desire, anger and greed, so that we can start walking on the path of shreyas or the auspicious, the path of the divine qualities. Only then do we become qualified to attain the supreme goal of self realization.
 
Having heard this, we probably have a question that arises in our minds. Every second of our lives, we are bombarded with a ton of desires. If our awareness level is high, we can regulate them some of the time, but not all of the time. Furthermore, anger can erupt and take over our mind within a microsecond. How can we, on our own, control desire, anger and greed? It is not easy. Anticipating this question, Shri Krishna answers it in the next shloka.

Bhagavad Gita Verse 21, Chapter 3

yadyadaacharati shreshthastattadevetaro janaha |
sa yatpramaanam kurute lokastadanuvartate || 21 ||
 
Whatever an ideal person does, so do other people (imitate him). Whatever standard he sets, other people follow.
 
yat yat  : just as
aacharati : a person does
shreshthaha : ideal
tat tat : in that manner
eva : only
itarah : other
janaha : people
sah : he
yat : whatever
pramaanam : standard
kurute : does
lokah : other people
tat : like him
anuvartate : they behave
 
In the previous verse, Shri Krishna provided the example of king Janaka who, though being a warrior king, achieved self-realization through performance of karma yoga. Here Shri Krishna puts forth yet another argument to Arjuna, knowing very well that Arjuna always put others first before himself. Shri Krishna said that whosoever looked up to Arjuna as a role model would also take to this path if Arjuna followed it.
 
Now, an extremely important but subtle point made by Shri Krishna is hidden in the phrase "ideal person does". He wants us to realize that actions speak louder than words. For instance, we cannot expect our children to not drink alcohol or smoke if we preach to them, but drink and smoke ourselves. Not just children, but most people watch what we do and not what we say. Therefore, Shri Krishna urges us to practice karmayoga, and not to simply tell people that we are learning it and so on.
 
So in addition to urging us and Arjuna to perform karmayoga, Shri Krishna also reveals an important leadership lesson. The best way to lead is to lead by example, and not by making flowery speeches or hiring motivational speakers. This point is not just echoed in the management texts of today, but also in spiritual masterpieces such as the Dasbodh by Samarth Ramdas Swami.