This is the same as the basis of most Asian philosophy: because of ignorance (avidya: lack of knowing), in other words, because our consciousness is asleep (in "a fog and unable to see") and does not perceive divinity, we feel "isolated", separate from divinity. That misperception gives the feeling of "I" and is fearful, because it feels alone, isolated. It then seeks comfort in sensations, ideas, beliefs. That is why Asian traditions assert that suffering is based on a mistaken perception of self.