As they form their identities over time and seek to affirm their own worth in the face of the goodness and the ambiguities of being in relationship, human beings must choose between accepting or rejecting God's love and God's promise. God gives human beings this choice precisely because of God's love for human persons. God respects the inviolable dignity of the human person and their absolute worth as moral agents, as people who can make moral decisions. Christian faith affirms the worth and dignity of all human beings and God's boundless love for humanity. However, individual human beings, situated as they are in particular historical circumstances, have to make choices and to act, in ways that realise their own and other's dignity. Such ways of acting 'incarnate' God's love in the world. Because they are free, rational and relational, human beings can choose to tear down and destroy the beauty and goodness that God has given to them. On the other hand they can choose to hear God's call when God asks them to care for the world, and deeply love all that is in it. This is the fundamental choice that all human beings face, a choice that all human beings must make.
The Catholic perspective promotes human dignity, the essential worth or dignity of the human person as made in the image and likeness of God. Each human being is unique and unrepeatable and loved and called by God. This means that every human being, in every circumstance, is good. This is not to say that they are morally good. Our moral goodness or moral badness is based on the moral decisions we make. Rather, to affirm the worth or dignity of the human person is to affirm that it is a good thing that he or she exists, that his or her existence is desired by God and that his or her existence is worthwhile. The dignity of the human person is the foundation of a moral vision for society (United States Conference of Catholic Bishops, 2013). Catholic thinking about sexuality and relationships is based on this basic affirmation of the equal worth of all human beings.
The sanctity of life is one way of giving expression to this basic affirmation of the worth or dignity of all human beings. When the Catholic Church affirms the sanctity of life it affirms that it is good that a particular human being exists rather than the reverse. the existence of each human person is willed by God and human beings have no right to destroy that existence. To say that life is sacred is to say, no matter who you are, no matter what you have done, no matter what you will do, the simple fact that you exist as a specific human being is enough for you to be considered worthy of life, worthy of respect and worthy of those things that will help you to flourish rather than perish.
The body is good. We affirmed above that the human being is good, not in a moral sense, but in the sense that it is good that any particular human exists. The same is true for the body as part of that human being created in the image of God. In other words, because we are created in the image of God as bodily beings, the human body constitutes part of what gives humans their fundamental and equal dignity or worth. The goodness, worth and dignity of the body, of our human flesh, is further affirmed by Catholic belief in the Incarnation. The idea that God chose to become a human being, to enter into the limitations of a specific human body in a specific time and place, gives a profound meaning to our fleshiness. God has chosen to become like us in every way but sin, and in so doing saved us from the limitations of this fleshiness of ours. Through the incarnation, death and resurrection of Jesus, we are freed from death as the ultimate limitation of our bodily existence. Jesus is raised not as a spirit. Jesus is raised with a glorified body. In other words, our very bodiliness is part of our future as much as it is part of our present.