Based on Bhagavad Gita Chapter 12, Text 15
Good teachers give explanations; great teachers give explanations and examples. Thus a great sports coach doesn’t just explain to budding sportspersons what to do, but also gives examples of sports champions who do it. Those examples are not just descriptive but also prescriptive. As the champions are models for the novices, latent in descriptions about them is the prescription: “you too should do like this and become like this.”
Krishna being the greatest teacher often uses in the Bhagavad-gita this same strategy of being explicitly descriptive and implicitly prescriptive. Acting as our spiritual coach, Krishna repeatedly describes champion spiritualists, the pure devotees. For example, he describes (12.15) the advanced devotee to be one who neither rejoices nor grieves, who neither laments nor desires, and who renounces both auspicious and inauspicious things. This verse is overtly descriptive; it outlines the characteristics of advanced spiritualists. Simultaneously, it is covertly prescriptive; it contains direction and inspiration for what we can and should become.
Those who consider the discipline required to apply this prescription as impractical, as asking for too much, as “not for me,” are like faint-hearted sports rookies who recoil from the discipline that has made champions champions. They are too chicken-hearted for pure devotion and they won’t get it.