The root of fear is the fear of death, which in Sanskrit is called Abhinivesha. Abhinivesha is one of the 5 Kleshas, the affliction, The Kleshas are the hindrances on the spiritual path, you must eliminate in order to experience Yoga, or union – oneness.
There are five kleshas with avidya being the first and fear the last . Avidya ( wrong knowledge) an elusive knowledge which is coming from information which you have no experience.
Avidya is subtle so much subtle that you cannot even be aware about , but if you work and practice choice less awareness when you don’t identify with non judgmental attitude then you can make improvement . The more we alert about Avidya, the weaker it influences our behaviors . Eventually, we feel that we are no longer victim of victims ; they simply happen to us. You can attract self fulfilling relationship and experience continually enriching experience