One of the most famous quotes from the Bhagavad Gita is:

"योगः कर्मसु कौशलम्" (yogaḥ karmasu kauśalam)
Translation: "Skill in action is yoga."

This quote emphasizes the importance of acquiring skill in action, or in other words, 
the importance of being a good teacher. According to the Bhagavad Gita,
a good teacher is someone who has mastered the art of skillful action and can impart that knowledge to others. 
This includes not only the technical aspects of teaching,
but also the ability to connect with and inspire students on a deeper level.