Evangelium Vitae §54

⁵⁴ As explicitly formulated, the precept "You shall not kill" is strongly negative: it indicates the extreme limit which can never be exceeded. Implicitly, however, it encourages a positive attitude of absolute respect for life; it leads to the promotion of life and to progress along the way of a love which gives, receives and serves. The people of the Covenant, although slowly and with some contradictions, progressively matured in this way of thinking, and thus prepared for the great proclamation of Jesus that the commandment to love one's neighbour is like the commandment to love God; "on these two commandments depend all the law and the prophets" (cf. Mt 22:36-40). Saint Paul emphasizes that "the commandment ... you shall not kill ... and any other commandment, are summed up in this phrase: ?You shall love your neighbour as yourself' " (Rom 13:9; cf. Gal 5:14). Taken up and brought to fulfilment in the New Law, the commandment "You shall not kill" stands as an indispensable condition for being able "to enter life" (cf. Mt 19:16-19). In this same perspective, the words of the Apostle John have a categorical ring: "Anyone who hates his brother is a murderer, and you know that no murderer has eternal life abiding in him" (1 Jn 3:15). From the beginning, the living Tradition of the Church-as shown by the Didache, the most ancient non-biblical Christian writing-categorically repeated the commandment "You shall not kill": "There are two ways, a way of life and a way of death; there is a great difference between them... In accordance with the precept of the teaching: you shall not kill ... you shall not put a child to death by abortion nor kill it once it is born ... The way of death is this: ... they show no compassion for the poor, they do not suffer with the suffering, they do not acknowledge their Creator, they kill their children and by abortion cause God's creatures to perish; they drive away the needy, oppress the suffering, they are advocates of the rich and unjust judges of the poor; they are filled with every sin. May you be able to stay ever apart, o children, from all these sins!". As time passed, the Church's Tradition has always consistently taught the absolute and unchanging value of the commandment "You shall not kill". It is a known fact that in the first centuries, murder was put among the three most serious sins-along with apostasy and adultery-and required a particularly heavy and lengthy public penance before the repentant murderer could be granted forgiveness and readmission to the ecclesial community.