A physician told me the true story of a woman in a hospital prepared to have an abortion. When the doctor noticed her diet was only vegetables, he asked why she did not eat meat. The woman answered, "Because I don't like killing."
The Church clearly teaches what common sense, at least commonly, understands: abortion is wrong because it kills a human being.
The woman in the hospital did not "like" killing animals, but was willing to kill her own child. Yet at the core of Church teaching on abortion is the truth that human life is uniquely set apart from other life forms because of its relationship with God the Creator. In his encyclical, The Gospel of Life, Pope John Paul II asks,
"Why is life good?...The life which God gives man is quite different from the life of all other living creatures, inasmuch as man, although formed from the dust of the earth...is a manifestation of God in the world, a sign of his presence, a trace of his glory... Man has been given a sublime dignity, based on the intimate bond which unites him to his Creator: in man there shines forth a reflection of God himself" (#34).
It is because human beings are created in the image and likeness of God that the Church opposes all attacks on human life and dignity. The teaching against abortion is rooted in the Church's rejection of all violence against the human person (see Vatican II's Pastoral Constitution on the Church in the Modern World, Gaudium et Spes #27).
The only proper response to the human person is love. No individual or group can be used or dominated by others. Before the moral law we are all absolutely equal. (See The Gospel of Life #57, and The Splendor of Truth #96).
In The Gospel of Life the Pope points out that we must pay special attention to the abortion tragedy because it is an attack on the most vulnerable and defenseless persons, because it is not only allowed but promoted as a "right," and because it occurs within the family, the "sanctuary of life," which should be the place of greatest love (see The Gospel of Life, #11).
When the Church says "Life is sacred," she means that life comes from God, belongs to God, and returns to God as its ultimate fulfillment. In the abortion controversy we are faced with the deep questions, "Who are we?" and "Whose are we?"
The Church corrects the false answers that the world gives. We do not belong to ourselves, as if all our "choices" were right just because we choose them. We do not belong, in an absolute sense, to our parents, as if they could decide to have us killed. Nor do we belong to the State, as if it could decide whether we live or die.
No, we belong to God, who called us into being by His wisdom and love. The right to life, then, is "inherent in the person by virtue of the creative act from which the person took his origin" (see Instruction on Respect for Human Life in its Origin and on the Dignity of Procreation, Donum Vitae (SCDF,1987) III, and the Catechism of the Catholic Church, 2273).
The Church reminds us that modern science makes it clear that a new human life begins at conception (see Declaration on Procured Abortion (SCDF,1974), #13, The Gospel of Life #60). Yet some try to say that not all "human beings" are "human persons" with rights. The Pope makes note of this and asks, "How could a human individual not be a human person?" The teaching against abortion is, in any case, independent of theories about ensoulment and the onset of personhood, precisely because abortion challenges God's dominion over the entire process of human development, and also because even when in doubt, the willingness to kill what is probably human is the willingness to kill what is human (See The Gospel of Life #60).
In a confirmation of the Church's constant teaching on abortion, the Pope says in The Gospel of Life,
"Given such unanimity in the doctrinal and disciplinary tradition of the Church, Paul VI was able to declare that this tradition is unchanged and unchangeable. Therefore, by the authority which Christ conferred upon Peter and his Successors, in communion with the Bishops - who on various occasions have condemned abortion and who in the aforementioned consultation, albeit dispersed throughout the world, have shown unanimous agreement concerning this doctrine - I declare that direct abortion, that is, abortion willed as an end or as a means, always constitutes a grave moral disorder, since it is the deliberate killing of an innocent human being. This doctrine is based upon the natural law and upon the written Word of God, is transmitted by the Church's Tradition and taught by the ordinary and universal Magisterium" (#62).
It should be noted that the teaching "is based upon the natural law." It is accessible to human reason, and is not simply a "religious teaching." One cannot say "Catholics oppose abortion; I am not a Catholic, so I don't have to be pro-life" any more than one can say, "Catholics oppose stealing; I am not a Catholic, so I can steal." Justice is not denominational.
The Pope also points out that abortion is wrong even if it is a means to a good end. The best of intentions cannot make a direct abortion right.
The Vatican's summary of The Gospel of Life points out that the wording of the Pope here reflects the wording of the Second Vatican Council's Dogmatic Constitution On the Church when that document describes the conditions under which the Church's Magisterium teaches Christ's doctrine infallibly (Lumen Gentium #25).
Jesus Christ not only reveals God to us, but He reveals us to ourselves. By His life and especially His death, He shows that as He was a man "for others," so we too find our fulfillment in giving ourselves away. "No one has greater love than this, to lay down one's life for one's friends" (Jn.15:13). Abortion is the opposite of love. Love says, "I sacrifice myself for the good of the other person." Abortion says, "I sacrifice the other person for the good of myself."
Christ is Life and He is Love. The Church is firmly pro-life not because it is a "male-dominated hierarchy," but precisely because she is feminine. She is the Bride of Christ, and the Mother of the faithful. We are her children, and hence we are the people of Life. That is way abortion can have no place among us. That is why we are sent into the world to eliminate it (see The Gospel of Life #78). And life will prevail, because death has been conquered in Christ. "Where, O death, is your victory? Where, O death, is your sting?...Thanks be to God, who gives us the victory through our Lord Jesus Christ" (1Cor.15:55,57).