Question One: On Undue Worship of the True God

S. Th. II-II, q. 93.

771. Undue worship of the true God (ongeschikte eeredienst) is twofold, either because it is false or because it is superfluous. - For not only every falsity in divine worship imports a certain irreverence toward God, but also whatever superfluity, vanity, or uselessness does nothing toward the end of worship.

772. False or pernicious worship is that through which something false is signified and which contains a pernicious lie:

a) Either on the part of the thing signified, when an act assumed for divine worship signifies something false which does not agree with the signification of worship, for example, if someone uses ceremonies of the Old Law which signify Christ as about to come; if someone proposes false miracles, revelations, prophecies as true; one who proposes false relics to be venerated, or exhibits an image falsely portentous (can. 1283-86, and 2326); one who invents miracles or stories to be found in the Scriptures.

b) Or only on the part of the person worshiping, when someone, acting as a member of the Church, worships God contrary to the mode established by God or the Church, for example, if a faithful person deliberately fasted on the day of Easter, with other days excluded. This happens chiefly in public worship, when someone worships God in the name of the Church who is not a minister of the Church or not deputed to such an act, for example, if a layman or a priest excommunicated by name were to celebrate Mass in the name of the Church, or if a minister performs ceremonies, administers sacraments, by a rite contrary to the will and ordinance of the Church, or by private authority proposes things as if they were ordered by the Church to the worship of God: for he is a falsifier who in the name of another proposes certain things for which he is not deputed (a. 1).

It is a sin from its genus and ordinarily mortal: a pernicious lie in a very grave matter.

Nevertheless Noldin notes, Th. M. II, n. 149, 2: "It is said for the most part, because it seems that it must be conceded that the superstition of false worship is sometimes a venial sin on account of smallness of matter: thus if a preacher in a miraculous story otherwise true added a false circumstance (or one not investigated), or invented an entire story (not miraculous) to move the people more, this could be a venial sin, both because falsity is not employed immediately for worshiping God, and because this does not always greatly prejudice true religion."

773. Superfluous worship is that which does not have falsity in its signification, but is not proportioned to the end of divine worship. For the end is that man give glory to God and subject himself to Him in mind and body. But if something, so far as concerns itself, does not pertain to the glory of God, nor subjects the mind or body of man to God according to the institution and common custom of God and the Church, but is beyond it, this is vain and superfluous in divine worship (a. 2).

It is accustomed to be committed concerning number, color, position, time, etc., for example, a ceremony of hearing Mass before sunrise, with a certain number, position, order of candles, by a priest who is called John, or who has the stature of Christ; in Mass to kiss the foot of the chalice after the elevation; to form more crosses, or to say alleluia more times than has been instituted by the Church; to add or remove the Gloria, Creed, or ceremony besides the rubrics; strange devotions prohibited by the Sacred Congregation of Rites (can. 1261, 1385, 1388, 1399).

It is a sin from its genus venial; per accidens it can be mortal from contempt, scandal, a dishonest ceremony, a grave prohibition of the Church, as if someone were to violate a precept of the Church in order to honor a saint.