In the end of ones life would one only have oneself to belong to and only thyself to feel vulnerable?

You have only yourself, in the end. You cannot know the innermost reality of even those people you are closest to, like a spouse or child. They are a separate entity that you ultimately have no control over. When we judge others, we are in reality judging ourselves and projecting it onto others. This is the meaning of Christ's admonition, "Judge not, lest ye be judged." For, He knew that we are all alone even in a sea of people. When we seek to control others, we really need to gain control of ourselves. When we give control to another, we are really exercising full control of ourselves. This is the meaning of the saying, "In the kingdom of heaven, the last shall be first, and the first shall be last."