From Pope St. John Paul II’s encyclical Veritatis Splendor (1993):
The relationship between faith and morality shines forth with all its brilliance in the unconditional respect due to the insistent demands of the personal dignity of every man, demands protected by those moral norms which prohibit without exception actions which are intrinsically evil. The universality and the immutability of the moral norm make manifest and at the same time serve to protect the personal dignity and inviolability of man, on whose face is reflected the splendour of God (cf. Gen 9:5-6).
The unacceptability of “teleological”, “consequentialist” and “proportionalist” ethical theories, which deny the existence of negative moral norms regarding specific kinds of behaviour, norms which are valid without exception, is confirmed in a particularly eloquent way by Christian martyrdom, which has always accompanied and continues to accompany the life of the Church even today.
— Veritatis Splendor 90