The human person realizes the maturity of his or her identity in relation to other persons, by living in communion. Various kinds of human interpersonal communion enrich the persons who give and receive love within them and also build up and strengthen the "common life" they share.
But the space of ultimate, definitive belonging for the person is sacred. It is transcendent. The person is "aware" (in some fashion, even if not explicitly articulated) that he or she "belongs," radically, to a Mystery, a Reality-of-Love-and-Affirmation that cannot be reduced to any person or group or object that is merely of this contingent, finite universe. The heart of the person cries out for the unique belonging to the Mystery that calls him or her into being, into a vocation to freedom that is inviolable, a vocation to love the One who is Absolute.
The dignity of the human person is founded on this belonging-to-the-Absolute. Any other person or community or ruler of this world who pretends to take the place of the Absolute in relation to a human person or group of persons violates their dignity. Sometimes we see this carried out in brutally obvious fashion, in an openly totalitarian dictatorship with a ritual personality cult. It happens whenever persons are reduced to the status of "things" and given over to the domination of others to use or dispose of as they wish. It happens to some degree, or casts its shadow over any human relationship insofar as it is not shaped by respect and love, but rather slips into even the most subtle forms of manipulation or abuse.
Every natural human mode of belonging has its proper place within that fundamental vocation of belonging to the One who alone establishes a person's identity, corresponds to a person's freedom, and constitutes a person's ineradicable destiny and radical fulfillment.