Bhagavad Gita Verse 47, Chapter 18

shreyansvadharmo vigunaha paradharmaatsvanushthataat |
svabhaavaniyatam karma kurvannaapnoti kilbisham || 47 ||
 
One's duty, though devoid of merits, is superior to another's duty well performed. Doing the duty prescribed for one's nature, one does not incur sin.
 
shreyan : superior
svadharmaha : one's duty
vigunaha : devoid of merits
paradharmaat : than another's duty
svanushthataat : well performed
svabhaavaniyatam : prescribed for per one’s nature
karma : duty
kurvann : doing
na : does not
aapnoti : incur
kilbisham : sin
 
We now focus on the subject of svadharma, which is the set of actions termed as duty. As we saw earlier, our duty can only be understood by conducting self analysis to understand what our mental makeup, what our varna is. Some of us may be well suited for starting businesses, whereas some of us may be better suited for the service sector. But it is quite common to get enchanted by another person’s occupation since it generates more money, since it has glamour and fame, and so on. How should we deal with this situation?
 
Shri Krishna says that we should stick to performing our svadharma, no matter how profitable or how glamourous other occupations seem like. In the short term, if we pick up another occupation, it may seem like we are doing a great job. But in the long run, we will fall into trouble. We will run into some problem or the other on account of not being suitable for someone else’s occupation. We also will deprive society from giving it the level of service possible if we had stuck with what we are good at.
 
Harbouring likes and dislikes towards actions, preferring someone else's occupation to ours, has the effect of strengthening the ego, and hence should be avoided. Furthermore, in karma yoga, we are only expected to perform our best actions, and to not worry about the result. By performing our svadharma, by doing the best we can, we automatically the fear of the consequence of our action, whether or not it will be a merit or a sin. To perform actions fearlessly is a blessing in itself.

Bhagavad Gita Verse 35, Chapter 3

shreyaansvadharmo vigunaha paradharmaatsvanushthitaat |
svadharme nidhanam shreyaha paradharmo bhayaavahaha || 35 ||
 
Following one's own nature, though imperfect, is still better than following another's nature that is perfect. Even dying in one's nature is better, and the nature of another leads to danger.
 
shreyaan : is better
svadharmah : following one's nature
vigunaha : imperfect
paradharmaat : compared to other's nature
svanushthitaat : perfect
svadharme : in one's nature
nidhanam : dying
shreyaha : it is better
paradharmo : other's nature
bhayaavahaha : cause of fear and danger
 
On the surface, this shloka seems to contradict the previous shloka where Shri Krishna advocated that we should not let our likes and dislikes, i.e. our nature, take us away from our goal. Here, he seems to say that we should follow our nature instead. Let us try to analyze this paradox.
 
Earlier, we came across the notion of svadharma, which is work that one enjoys doing, has the aptitude and training for doing, and is not illegal or unethical. Svadharma is nothing but our strongest likes and desires, and only we can judge what they are.
 
Upon self-examination, we may find that we gravitate towards a career in art, or music, or science and so on. Let's say we determine that science is our strongest like. That now becomes our svadharma. We use the enormous pressure of our interest in science in the service of a higher goal, by becoming a researcher, for instance.
 
Another implication of this message is that the force generated by our svadharma should be used in evolution of our personality. A person with a strong desire to fight can become a soldier if he uses his svadharma in the service of his country. But he can also become a gangster if his svadharma is not dedicated to a higher ideal.
 
Therefore, what this shloka says is that once we have selected a strong desire as our svadharma, we should not let weaker likes or dislikes distract us from the svadharma. For example, let's say we are pursuing a PhD in science. We may come across someone following a different profession and who earns significantly more money. We should not cause our liking for more money to change our path. Not only will it help us reach our spiritual goal, we will have peace of mind too.
 
What is unique about this approach is that it emphasizes introspection over blind faith. The beauty of the Gita's teaching is that takes care of every person. There is no fixed rigid path - each one arrives at their own path through self-analysis. It is like a kitchen where each spice is unique, but has a distinct role to play in making a meal.