Fear seems to have many causes. Fear of loss, fear of failure, fear of being hurt, and so on, but ultimately all fear is the ego's fear of death, of annihilation. To the ego, death is always just around the corner. In this mind-identified state, fear of death affects every aspect of your life.
Eckhart TolleWith the egoic consciousness having become so dysfunctional, and now having at our disposal all these enormous technologies and scientific advances, if nothing changes the ego will use those things - as it already has been doing - and will amplify the technology that we now have. The scientific advances, to a large extent, will be used in the service of the ego, and they will become more and more destructive.
Eckhart Tolle