Summa Theologica, by St. Thomas Aquinas, , at sacred-texts.com
We must now consider the necessity of the sacraments; concerning which there are four points of inquiry:
(1) Whether sacraments are necessary for man's salvation?
(2) Whether they were necessary in the state that preceded sin?
(3) Whether they were necessary in the state after sin and before Christ?
(4) Whether they were necessary after Christ's coming?
Objection 1: It seems that sacraments are not necessary for man's salvation. For the Apostle says (1 Tim. 4:8): "Bodily exercise is profitable to little." But the use of sacraments pertains to bodily exercise; because sacraments are perfected in the signification of sensible things and words, as stated above (Q, A). Therefore sacraments are not necessary for the salvation of man.
Objection 2: Further, the Apostle was told (2 Cor. 12:9): "My grace is sufficient for thee." But it would not suffice if sacraments were necessary for salvation. Therefore sacraments are not necessary for man's salvation.
Objection 3: Further, given a sufficient cause, nothing more seems to be required for the effect. But Christ's Passion is the sufficient cause of our salvation; for the Apostle says (Rom. 5:10): "If, when we were enemies, we were reconciled to God by the death of His Son: much more, being reconciled, shall we be saved by His life." Therefore sacraments are not necessary for man's salvation.
On the contrary, Augustine says (Contra Faust. xix): "It is impossible to keep men together in one religious denomination, whether true or false, except they be united by means of visible signs or sacraments." But it is necessary for salvation that men be united together in the name of the one true religion. Therefore sacraments are necessary for man's salvation.
I answer that, Sacraments are necessary unto man's salvation for three reasons. The first is taken from the condition of human nature which is such that it has to be led by things corporeal and sensible to things spiritual and intelligible. Now it belongs to Divine providence to provide for each one according as its condition requires. Divine wisdom, therefore, fittingly provides man with means of salvation, in the shape of corporeal and sensible signs that are called sacraments.
The second reason is taken from the state of man who in sinning subjected himself by his affections to corporeal things. Now the healing remedy should be given to a man so as to reach the part affected by disease. Consequently it was fitting that God should provide man with a spiritual medicine by means of certain corporeal signs; for if man were offered spiritual things without a veil, his mind being taken up with the material world would be unable to apply itself to them.
The third reason is taken from the fact that man is prone to direct his activity chiefly towards material things. Lest, therefore, it should be too hard for man to be drawn away entirely from bodily actions, bodily exercise was offered to him in the sacraments, by which he might be trained to avoid superstitious practices, consisting in the worship of demons, and all manner of harmful action, consisting in sinful deeds.
It follows, therefore, that through the institution of the sacraments man, consistently with his nature, is instructed through sensible things; he is humbled, through confessing that he is subject to corporeal things, seeing that he receives assistance through them: and he is even preserved from bodily hurt, by the healthy exercise of the sacraments.
Reply to Objection 1: Bodily exercise, as such, is not very profitable: but exercise taken in the use of the sacraments is not merely bodily, but to a certain extent spiritual, viz. in its signification and in its causality.
Reply to Objection 2: God's grace is a sufficient cause of man's salvation. But God gives grace to man in a way which is suitable to him. Hence it is that man needs the sacraments that he may obtain grace.
Reply to Objection 3: Christ's Passion is a sufficient cause of man's salvation. But it does not follow that the sacraments are not also necessary for that purpose: because they obtain their effect through the power of Christ's Passion; and Christ's Passion is, so to say, applied to man through the sacraments according to the Apostle (Rom. 6:3): "All we who are baptized in Christ Jesus, are baptized in His death."
Objection 1: It seems that before sin sacraments were necessary to man. For, as stated above (A, ad 2) man needs sacraments that he may obtain grace. But man needed grace even in the state of innocence, as we stated in the FP, Q, A (cf. FS, Q, A; FS, Q, A). Therefore sacraments were necessary in that state also.
Objection 2: Further, sacraments are suitable to man by reason of the conditions of human nature, as stated above (A). But man's nature is the same before and after sin. Therefore it seems that before sin, man needed the sacraments.
Objection 3: Further, matrimony is a sacrament, according to Eph. 5:32: "This is a great sacrament; but I speak in Christ and in the Church." But matrimony was instituted before sin, as may be seen in Gn. 2. Therefore sacraments were necessary to man before sin.
On the contrary, None but the sick need remedies, according to Mat. 9:12: "They that are in health need not a physician." Now the sacraments are spiritual remedies for the healing of wounds inflicted by sin. Therefore they were not necessary before sin.
I answer that, Sacraments were not necessary in the state of innocence. This can be proved from the rectitude of that state, in which the higher (parts of man) ruled the lower, and nowise depended on them: for just as the mind was subject to God, so were the lower powers of the soul subject to the mind, and the body to the soul. And it would be contrary to this order if the soul were perfected either in knowledge or in grace, by anything corporeal; which happens in the sacraments. Therefore in the state of innocence man needed no sacraments, whether as remedies against sin or as means of perfecting the soul.
Reply to Objection 1: In the state of innocence man needed grace: not so that he needed to obtain grace by means of sensible signs, but in a spiritual and invisible manner.
Reply to Objection 2: Man's nature is the same before and after sin, but the state of his nature is not the same. Because after sin, the soul, even in its higher part, needs to receive something from corporeal things in order that it may be perfected: whereas man had no need of this in that state.
Reply to Objection 3: Matrimony was instituted in the state of innocence, not as a sacrament, but as a function of nature. Consequently, however, it foreshadowed something in relation to Christ and the Church: just as everything else foreshadowed Christ.
Objection 1: It seems that there should have been no sacraments after sin, before Christ. For it has been stated that the Passion of Christ is applied to men through the sacraments: so that Christ's Passion is compared to the sacraments as cause to effect. But effect does not precede cause. Therefore there should have been no sacraments before Christ's coming.
Objection 2: Further, sacraments should be suitable to the state of the human race, as Augustine declares (Contra Faust. xix). But the state of the human race underwent no change after sin until it was repaired by Christ. Neither, therefore, should the sacraments have been changed, so that besides the sacraments of the natural law, others should be instituted in the law of Moses.
Objection 3: Further, the nearer a thing approaches to that which is perfect, the more like it should it be. Now the perfection of human salvation was accomplished by Christ; to Whom the sacraments of the Old Law were nearer than those that preceded the Law. Therefore they should have borne a greater likeness to the sacraments of Christ. And yet the contrary is the case, since it was foretold that the priesthood of Christ would be "according to the order of Melchisedech, and not . . . according to the order of Aaron" (Heb. 7:11). Therefore sacraments were unsuitably instituted before Christ.
On the contrary, Augustine says (Contra Faust. xix) that "the first sacraments which the Law commanded to be solemnized and observed were announcements of Christ's future coming." But it was necessary for man's salvation that Christ's coming should be announced beforehand. Therefore it was necessary that some sacraments should be instituted before Christ.
I answer that, Sacraments are necessary for man's salvation, in so far as they are sensible signs of invisible things whereby man is made holy. Now after sin no man can be made holy save through Christ, "Whom God hath proposed to be a propitiation, through faith in His blood, to the showing of His justice . . . that He Himself may be just, and the justifier of him who is of the faith of Jesus Christ" (Rom. 3:25, 26). Therefore before Christ's coming there was need for some visible signs whereby man might testify to his faith in the future coming of a Saviour. And these signs are called sacraments. It is therefore clear that some sacraments were necessary before Christ's coming.
Reply to Objection 1: Christ's Passion is the final cause of the old sacraments: for they were instituted in order to foreshadow it. Now the final cause precedes not in time, but in the intention of the agent. Consequently, there is no reason against the existence of sacraments before Christ's Passion.
Reply to Objection 2: The state of the human race after sin and before Christ can be considered from two points of view. First, from that of faith: and thus it was always one and the same: since men were made righteous, through faith in the future coming of Christ. Secondly, according as sin was more or less intense, and knowledge concerning Christ more or less explicit. For as time went on sin gained a greater hold on man, so much so that it clouded man's reason, the consequence being that the precepts of the natural law were insufficient to make man live aright, and it became necessary to have a written code of fixed laws, and together with these certain sacraments of faith. For it was necessary, as time went on, that the knowledge of faith should be more and more unfolded, since, as Gregory says (Hom. vi in Ezech.): "With the advance of time there was an advance in the knowledge of Divine things." Consequently in the old Law there was also a need for certain fixed sacraments significative of man's faith in the future coming of Christ: which sacraments are compared to those that preceded the Law, as something determinate to that which is indeterminate: inasmuch as before the Law it was not laid down precisely of what sacraments men were to make use: whereas this was prescribed by the Law; and this was necessary both on account of the overclouding of the natural law, and for the clearer signification of faith.
Reply to Objection 3: The sacrament of Melchisedech which preceded the Law is more like the Sacrament of the New Law in its matter: in so far as "he offered bread and wine" (Gn. 14:18), just as bread and wine are offered in the sacrifice of the New Testament. Nevertheless the sacraments of the Mosaic Law are more like the thing signified by the sacrament, i.e. the Passion of Christ: as clearly appears in the Paschal Lamb and such like. The reason of this was lest, if the sacraments retained the same appearance, it might seem to be the continuation of one and the same sacrament, where there was no interruption of time.
Objection 1: It seems that there was no need for any sacraments after Christ came. For the figure should cease with the advent of the truth. But "grace and truth came by Jesus Christ" (Jn. 1:17). Since, therefore, the sacraments are signs or figures of the truth, it seems that there was no need for any sacraments after Christ's Passion.
Objection 2: Further, the sacraments consist in certain elements, as stated above (Q, A). But the Apostle says (Gal. 4:3, 4) that "when we were children we were serving under the elements of the world": but that now "when the fulness of time" has "come," we are no longer children. Therefore it seems that we should not serve God under the elements of this world, by making use of corporeal sacraments.
Objection 3: Further, according to James 1:17 with God "there is no change, nor shadow of alteration." But it seems to argue some change in the Divine will that God should give man certain sacraments for his sanctification now during the time of grace, and other sacraments before Christ's coming. Therefore it seems that other sacraments should not have been instituted after Christ.
On the contrary, Augustine says (Contra Faust. xix) that the sacraments of the Old Law "were abolished because they were fulfilled; and others were instituted, fewer in number, but more efficacious, more profitable, and of easier accomplishment."
I answer that, As the ancient Fathers were saved through faith in Christ's future coming, so are we saved through faith in Christ's past birth and Passion. Now the sacraments are signs in protestation of the faith whereby man is justified; and signs should vary according as they signify the future, the past, or the present; for as Augustine says (Contra Faust. xix), "the same thing is variously pronounced as to be done and as having been done: for instance the word 'passurus' [going to suffer] differs from 'passus' [having suffered]." Therefore the sacraments of the New Law, that signify Christ in relation to the past, must needs differ from those of the Old Law, that foreshadowed the future.
Reply to Objection 1: As Dionysius says (Eccl. Hier. v), the state of the New Law. is between the state of the Old Law, whose figures are fulfilled in the New, and the state of glory, in which all truth will be openly and perfectly revealed. Wherefore then there will be no sacraments. But now, so long as we know "through a glass in a dark manner," (1 Cor. 13:12) we need sensible signs in order to reach spiritual things: and this is the province of the sacraments.
Reply to Objection 2: The Apostle calls the sacraments of the Old Law "weak and needy elements" (Gal. 4:9) because they neither contained nor caused grace. Hence the Apostle says that those who used these sacraments served God "under the elements of this world": for the very reason that these sacraments were nothing else than the elements of this world. But our sacraments both contain and cause grace: consequently the comparison does not hold.
Reply to Objection 3: Just as the head of the house is not proved to have a changeable mind, through issuing various commands to his household at various seasons, ordering things differently in winter and summer; so it does not follow that there is any change in God, because He instituted sacraments of one kind after Christ's coming, and of another kind at the time of the Law. because the latter were suitable as foreshadowing grace; the former as signifying the presence of grace,