Obj. 3:  Further, the commands of the apostles did not lead men into sin.  But it was commanded by apostolic decree that the Gentiles should observe certain ceremonies of the Law:  for it is written (Acts 15:28, 29):  “It hath seemed good to the Holy Ghost and to us, to lay no further burden upon you than these necessary things:  that you abstain from things sacrificed to idols, and from blood, and from things strangled, and from fornication.”  Therefore the legal ceremonies can be observed since Christ’s Passion without committing mortal sin.

On the contrary, The Apostle says (Gal. 5:2):  “If you be circumcised, Christ shall profit you nothing.”  But nothing save mortal sin hinders us from receiving Christ’s fruit.  Therefore since Christ’s Passion it is a mortal sin to be circumcised, or to observe the other legal ceremonies.

I answer that, All ceremonies are professions of faith, in which the interior worship of God consists.  Now man can make profession of his inward faith, by deeds as well as by words:  and in either profession, if he make a false declaration, he sins mortally.  Now, though our faith in Christ is the same as that of the fathers of old; yet, since they came before Christ, whereas we come after Him, the same faith is expressed in different words, by us and by them.  For by them was it said:  “Behold a virgin shall conceive and bear a son,” where the verbs are in the future tense:  whereas we express the same by means of verbs in the past tense, and say that she “conceived and bore.”  In like manner the ceremonies of the Old Law betokened Christ as having yet to be born and to suffer:  whereas our sacraments signify Him as already born and having suffered.  Consequently, just as it would be a mortal sin now for anyone, in making a profession of faith, to say that Christ is yet to be born, which the fathers of old said devoutly and truthfully; so too it would be a mortal sin now to observe those ceremonies which the fathers of old fulfilled with devotion and fidelity.  Such is the teaching of Augustine (Contra Faust. xix, 16), who says:  “It is no longer promised that He shall be born, shall suffer and rise again, truths of which their sacraments were a kind of image:  but it is declared that He is already born, has suffered and risen again; of which our sacraments, in which Christians share, are the actual representation.”

Reply Obj. 1:  On this point there seems to have been a difference of opinion between Jerome and Augustine.  For Jerome (Super Galat. ii, 11, seqq.) distinguished two periods of time.  One was the time previous to Christ’s Passion, during which the legal ceremonies were neither dead, since they were obligatory, and did expiate in their own fashion; nor deadly, because it was not sinful to observe them.  But immediately after Christ’s Passion they began to be not only dead, so as no longer to be either effectual or binding; but also deadly, so that whoever observed them was