To claim the right to abortion, infanticide and euthanasia, and to recognize that right in law, means to attribute to human freedom a perverse and evil significance: that of an absolute power over others and against others. This is the death of true freedom: “Truly, truly, I say to you, every one who commits sin is a slave to sin” (Jn 8:34).

21. In seeking the deepest roots of the struggle between the “culture of life” and the “culture of death“, we cannot restrict ourselves to the perverse idea of freedom mentioned above. We have to go to the heart of the tragedy being experienced by modern man: the eclipse of the sense of God and of man, typical of a social and cultural climate dominated by secularism, which, with its ubiquitous tentacles, succeeds at times in putting Christian communities themselves to the test. Those who allow themselves to be influenced by this climate easily fall into a sad vicious circle: when the sense of God is lost, there is also a tendency to lose the sense of man, of his dignity and his life; in turn, the systematic violation of the moral law, especially in the serious matter of respect for human life and its dignity, produces a kind of progressive darkening of the capacity to discern God’s living and saving presence. …

28. This situation, with its lights and shadows, ought to make us all fully aware that we are facing an enormous and dramatic clash between good and evil, death and life, the “culture of death” and the “culture of life”. We find ourselves not only “faced with” but necessarily “in the midst of” this conflict: we are all involved and we all share in it, with the inescapable responsibility of choosing to be unconditionally pro-life. …

Therefore, by the authority which Christ conferred upon Peter and his Successors, and in communion with the Bishops of the Catholic Church, I confirm that the direct and voluntary killing of an innocent human being is always gravely immoral. This doctrine, based upon that unwritten law which man, in the light of reason, finds in his own heart (cf. Rom 2:14-15), is reaffirmed by Sacred Scripture, transmitted by the Tradition of the Church and taught by the ordinary and universal Magisterium. …

58. Among all the crimes which can be committed against life, procured abortion has characteristics making it particularly serious and deplorable. The Second Vatican Council defines abortion, together with infanticide, as an “unspeakable crime”. …

The basis of these values cannot be provisional and changeable “majority” opinions, but only the acknowledgment of an objective moral law which, as the “natural law” written in the human heart, is the obligatory point of reference for civil law itself. If, as a result of a tragic obscuring of the collective conscience, an attitude of skepticism were to succeed in bringing into question even the fundamental principles of the moral law, the democratic system itself would be shaken in its foundations, and would be reduced to a mere mechanism for regulating different and opposing interests on a purely empirical basis. …

73. Abortion and euthanasia are thus crimes which no human law can claim to legitimize. There is no obligation in conscience to obey such laws; instead there is a grave and clear obligation to oppose them by conscientious objection.

Evangelium Vitae (25 March 1995) | John Paul II