Peacemakers are those who love, defend and promote life in its fullness
4. The path to the attainment of the common good and to peace is above all that of respect for human life in all its many aspects, beginning with its conception, through its development and up to its natural end. True peacemakers, then, are those who love, defend and promote human life in all its dimensions, personal, communitarian and transcendent. Life in its fullness is the height of peace. Anyone who loves peace cannot tolerate attacks and crimes against life.
Those who insufficiently value human life and, in consequence, support among other things the liberalization of abortion, perhaps do not realize that in this way they are proposing the pursuit of a false peace. The flight from responsibility, which degrades human persons, and even more so the killing of a defenceless and innocent being, will never be able to produce happiness or peace. Indeed how could one claim to bring about peace, the integral development of peoples or even the protection of the environment without defending the life of those who are weakest, beginning with the unborn. Every offence against life, especially at its beginning, inevitably causes irreparable damage to development, peace and the environment. Neither is it just to introduce surreptitiously into legislation false rights or freedoms which, on the basis of a reductive and relativistic view of human beings and the clever use of ambiguous expressions aimed at promoting a supposed right to abortion and euthanasia, pose a threat to the fundamental right to life.
There is also a need to acknowledge and promote the natural structure of marriage as the union of a man and a woman in the face of attempts to make it juridically equivalent to radically different types of union; such attempts actually harm and help to destabilize marriage, obscuring its specific nature and its indispensable role in society.
These principles are not truths of faith, nor are they simply a corollary of the right to religious freedom. They are inscribed in human nature itself, accessible to reason and thus common to all humanity. The Church’s efforts to promote them are not therefore confessional in character, but addressed to all people, whatever their religious affiliation. Efforts of this kind are all the more necessary the more these principles are denied or misunderstood, since this constitutes an offence against the truth of the human person, with serious harm to justice and peace.
Consequently, another important way of helping to build peace is for legal systems and the administration of justice to recognize the right to invoke the principle of conscientious objection in the face of laws or government measures that offend against human dignity, such as abortion and euthanasia.One of the fundamental human rights, also with reference to international peace, is the right of individuals and communities to religious freedom. At this stage in history, it is becoming increasingly important to promote this right not only from the negative point of view, as freedom from – for example, obligations or limitations involving the freedom to choose one’s religion – but also from the positive point of view, in its various expressions, as freedom for – for example, bearing witness to one’s religion, making its teachings known, engaging in activities in the educational, benevolent and charitable fields which permit the practice of religious precepts, and existing and acting as social bodies structured in accordance with the proper doctrinal principles and institutional ends of each.
-from the Holy Father's Message for the World Day of Peace