1. The analysis of purity is an indispensable completion of the words Christ spoke in the Sermon on the Mount, which our present reflections are centered on. When explaining the correct meaning of the commandment, "You shall not commit adultery," Christ appealed to the interior man. At the same time he specified the fundamental dimension of purity that marks the relations between man and woman both in marriage and outside it. The words, "But I say to you that everyone who looks at a woman lustfully has already committed adultery with her in his heart" (Mt 5:27-28), express what is opposed to purity. At the same time, these words demand the purity which, in the Sermon on the Mount, is included in the list of the beatitudes: "Blessed are the pure in heart, for they shall see God" (Mt 5:8). In this way Christ appealed to the human heart. He called upon it and did not accuse it, as we have already clarified.
2. Christ sees in the heart, in man's inner self, the source of purity—but also of moral impurity—in the fundamental and most generic sense of the word. That is confirmed, for example, by the answer he gave to the Pharisees, who were scandalized by the fact that his disciples "transgress the tradition of the elders. For they do not wash their hands when they eat" (Mt 15:2). Jesus then said to those present: "Not what goes into the mouth defiles a man, but what comes out of the mouth defiles a man" (Mt 15:11). Answering Peter's question, he explained these words to his disciples as follows: "What comes out of the mouth proceeds from the heart, and this defiles a man. For out of the heart come evil thoughts, murder, adultery, fornication, theft, false witness, slander. These are what defile a man, but to eat with unwashed hands does not defile a man" (cf. Mt 15:18-20; also Mk 7:20-23).
When we say "purity" or "pure," in the first meaning of these words, we indicate what contrasts with what is dirty. "To dirty" means "to make filthy," "to pollute." That referred to the various spheres of the physical world. For example, we talk of a dirty road or a dirty room; we also talk of polluted air. In the same way man can be filthy, when his body is not clean. The body must be washed to remove dirt.
The Old Testament tradition attributed great importance to ritual ablutions, for example, to wash one's hands before eating, which the above-mentioned text spoke of. Many detailed prescriptions concerned the ablutions of the body in relation to sexual impurity, understood in the exclusively physiological sense, to which we have referred previously (cf. Lv 15). According to the medical science of the time, the various ablutions may have corresponded to hygienic prescriptions. Since they were imposed in God's name and contained in the sacred books of the Old Testament legislation, their observance indirectly acquired a religious meaning. They were ritual ablutions and, in the life of the people of the old covenant, they served ritual "purity."
Purity in the moral sense
3. In relation to the aforesaid juridico-religious tradition of the old covenant, an erroneous way of understanding moral purity developed.(1) It was often taken in the exclusively exterior and material sense. In any case, an explicit tendency to this interpretation spread. Christ opposed it radically. Nothing from outside makes one filthy, no "material" dirt makes one impure in the moral, that is, interior sense. No ablution, not even of a ritual nature, is capable in itself of producing moral purity. This has its exclusive source within man. It comes from the heart.
Probably the respective prescriptions in the Old Testament (for example, those found in Leviticus 15:16-24; 18:lff., or 12:1-5) served, in addition to hygienic purposes, to attribute a certain dimension of interiority to what is corporeal and sexual in the human person. In any case, Christ took good care not to connect purity in the moral (ethical) sense with physiology and its organic processes. In the light of the words of Matthew 15:18-20, quoted above, none of the aspects of sexual "dirtiness," in the strictly bodily, biophysiological sense, falls by itself into the definition of purity or impurity in the moral (ethical) sense.
A general concept
4. The aforesaid assertion (Mt 15:18-20) is important above all for semantic reasons. Speaking of purity in the moral sense, that is, of the virtue of purity, we use an analogy, according to which moral evil is compared precisely to uncleanness. Certainly this analogy has been a part of the sphere of ethical concepts from the most remote times. Christ took it up again and confirmed it in all its extension: "What comes out of the mouth proceeds from the heart, and this defiles a man." Here Christ spoke of all moral evil, of all sin, that is, of transgressions of the various commandments. He enumerates "evil thoughts, murder, adultery, fornication, theft, false witness, slander," without confining himself to a specific kind of sin. It follows that the concept of purity and impurity in the moral sense is in the first place a general concept, not a specific one. All moral good is a manifestation of purity, and all moral evil is a manifestation of impurity.
Matthew 15:18-20 does not limit purity to one area of morality, namely, to the one connected with the commandment, "You shall not commit adultery" and "Do not covet your neighbor's wife," that is, to the one that concerns the relations between man and woman, linked to the body and to the relative concupiscence. Similarly we can understand the beatitude of the Sermon on the Mount, addressed to "the pure in heart," both in the general and in the more specific sense. Only the actual context will make it possible to delimit and clarify this meaning.
The flesh and the spirit
5. The wider and more general meaning of purity is present also in St. Paul's letters. In them we shall gradually pick out the contexts which explicitly limit the meaning of purity to the bodily and sexual sphere, that is, to that meaning which we can grasp from Christ's words in the Sermon on the Mount on lust. This is already expressed in "looking at a woman," and is regarded as equivalent to "committing adultery in one's heart" (cf. Mt 5:27-28).
St. Paul is not the author of the words about the three forms of lust. As we know, they occur in the First Letter of John. John spoke of the opposition within man between God and the world, between what comes "from the Father" and what comes "from the world" (cf. 1 Jn 2:16-17). This opposition is born in the heart and penetrates into man's actions as "the lust of the flesh and the lust of the eyes and the pride of life." Similarly, St. Paul points out another contradiction in the Christian. It is the opposition and at the same time the tension between the "flesh" and the "Spirit" (written with a capital letter, that is, the Holy Spirit). "But I say, walk by the Spirit, and do not gratify the desires of the flesh. For the desires of the flesh are against the Spirit, and the desires of the Spirit are against the flesh. For these are opposed to each other, to prevent you from doing what you would" (Gal 5:16-17). It follows that life "according to the flesh" is in opposition to life "according to the Spirit." "For those who live according to the flesh set their minds on the things of the flesh, but those who live according to the Spirit set their minds on the things of the Spirit" (Rom 8:5).
In subsequent analyses we shall seek to show that purity—the purity of heart which Christ spoke of in the Sermon on the Mount—is realized precisely in life according to the Spirit.
1) Alongside a complex system of prescriptions concerning ritual purity, on which legal casuistry was based, the concept of moral purity also existed in the Old Testament. It was handed down by means of two channels.
The Prophets demanded behavior in conformity with God's will, which presupposes conversion of heart, interior obedience and complete uprightness before him (cf. for example, Is 1:10-20; Jer 4:14; 24:7; Ez 36:25ff.). A similar attitude is required also by the Psalmist:
Who shall ascend the hill of the Lord... / He who has clean hands and a pure heart... / will receive blessing from the Lord (Ps 24:3-5).
According to the priestly tradition, man is aware of his deep sinfulness and, not being able to purify himself by his own power, he beseeches God to bring about this change of heart, which can only be the work of a creative act of his:
Create in me a clean heart, O God... / wash me, and I shall be whiter than snow... / a broken and contrite heart, O God, you will not despise (Ps 51:10, 7, 17).
Both Old Testament channels meet in the beatitude of the "pure in heart" (Mt 5:8), even if its verbal formulation seems to be closer to Psalm 24 (cf. J. Dupont, Les Béatitudes, vol. III; Les Evangélistes [Paris: Gabalda, 1973], pp. 603-604).
Source: L'Osservatore Romano