Bhagavad Gita Verse 45, Chapter 11

adrishtapoorvam hrishitosmi drishtvaa bhayena cha pravyathitam mano me |
tadeva me darshaya devaroopam praseeda devesha jagannivaasa || 45 ||
 
Seeing you form that was never seen before, I am overjoyed and (yet) fearful, my mind is disturbed. Show me that divine form. Be pleased, O Lord of lords, O abode of the universe.
 
adrishtapoorvam : prior unseen
hrishitaha : overjoyed
asmi : I am
drishtvaa : seeing
bhayena : fearful
cha : and
pravyathitam : disturbed
manaha : mind
me : my
tadeva : that
me : to me
darshaya : show
devaroopam : divine form
praseeda : be pleased
devesha : O Lord of lords
jagannivaasa : O abode of the universe
 
Fear is one of our most primal emotions. At some point or the other in our lives, we have encountered fear of losing our job, losing a loved one, fear of an angry confrontation, stage fright and so on. But we can boil all kinds of fear down to three things. First, the fear of losing something that is “ours”. This is the fear of losing our life, our job, our loved ones and so on. Next is the fear of loss of knowledge, or being duped. Third is the fear of losing joy and happiness, fear of sorrow in other words. We can sum it up in this manner: we are afraid of losing our existence, knowledge and happiness.
 
However, if we recall the teaching of the Gita so far, especially from the second chapter, we know that our true nature is the aatmaa, the eternal essence which is infinite existence, knowledge and happiness. So then, the cause of fear is the ego, the delusion that we are not the eternal essence. There is no scope for fear when we know our true nature as the infinite eternal essence. But if we assume that “I am the body”, then all the problems and fears of the body such as disease, old age, death etc become our problems. The fear of death, which is actually the fear of losing the existence of the body, becomes our fear.
 
So then, why did Arjuna fear Shri Krishna’s cosmic form? For a brief moment, Arjuna’s ego had vanished when he considered himself part and parcel of the cosmic form. When his ego came back, it brought with it all the incorrect associations with the body, mind and so on. Arjuna then saw the cosmic form as something outside of himself, something that could destroy him. He acknowledged his fear to Shri Krishna, begging him to go back to his original form.