ashradyadhaanaahaa purushaa dharmasyaasya parantapa |
apraapya maam nivartante mrityusamsaaravartmani || 3 ||

People who do not have faith in this prescription, O scorcher of foes, do not attain me. They return to the path of the mortal world.
ashradyadhaanaahaa = not having faith in
purushaa = people
dharmasya = prescription
asya = this
parantapa = O scorcher of foes
apraapya = not attain
maam = me
nivartante = return
mrityu = mortal
samsaara = world
vartmani = path
Like any good teacher, Shri Krishna first glorifies the knowledge that he is about to teach, then points out the qualifications of the worthy student. Addressing Arjuna as the “scorcher of foes”, he says that they key qualification required to receive this teaching is that of faith. If we do not have faith, we continue following our old ways, only to be trapped in this endless cycle of creation and dissolution.
Why is there so much importance placed in faith? Without faith, we will not have the inclination to fully understand any teaching. Even in school or college, we will not take the extra effort to inquire, ask questions, read books and resolve our doubts unless we have faith in the subject and the teacher. It is even more important in this kind of knowledge.
So then, what happens to those that do not have faith? Shri Krishna says that such people do not attain Ishvara. They have faith in their sense organs and their corresponding sense pleasures. These people still think that feeding their senses with more food, entertainment as well as bodily and intellectual comforts will result in long-lasting happiness. This misplaced faith further ensnares them in the path of the mortal world, which that of birth, old age, disease and death, over and over again.
Having sufficiently introduced the chapter, Shri Krishna delivers the main message of this chapter in the following two shlokas.