"Roman Catholic Catechism clearly teaches that Rome views circumcision under the Old Covenant in the same exact sacramental sense as they veiw baptism under the New Covenant."
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I don't know what is meant by "exact same sacramental sense." which you posted on the 'Great Whore' thread, but
circumcision is not a Sacrament of the New Law but is a Sacrament of the Old Law.
The Roman Catechism states:
"Speaking of circumcision, a Sacrament of the Old Law which was given to Abraham, the father of all believers, the Apostle in his Epistle to the Romans, says: And he received the sign of circumcision, a seal of the justice of the faith." (Part II, "Proof from Scripture," citing Rom 4:11)
St. Thomas Aquinas also explains why the ceremonies of the Old Law (but not the sacrifices) were sacraments:
"The sacrifice of the New Law, viz. the Eucharist, contains Christ Himself, the Author of our Sanctification: for He sanctified 'the people by His own blood' (Heb 13:12). Hence this Sacrifice is also a sacrament. But the sacrifices of the Old Law did not contain Christ, but foreshadowed Him; hence they are not called sacraments. In order to signify this there were certain sacraments apart from the sacrifices of the Old Law, which sacraments were figures of the sanctification to come. Nevertheless to certain consecrations certain sacrifices were united." (ST, Ia-IIae, Q.101, A.4, ad 2 -- http://bit.ly/1h76WUX)
So circumcision was like unto baptism in that they both are Sacraments of Faith which remit sins, original and actual, but because circumcision was done in view of the future merits of Christ and baptism is done with a view towards the past and present, their modes are different.
St. Paul himself draws the comparison between baptism and circumcision:
"In whom also you are circumcised with circumcision not made by hand, in despoiling of the body of the flesh, but in the circumcision of Christ: buried with him in baptism, in whom also you are risen again by the faith of the operation of God, who hath raised him up from the dead." (Col 2:11-12)
Baptism and circumcision are the Sacrament of Faith by which a person professes faith in Christ. Therefore, it is impossible to try to oppose faith to the sacrament and ask in which part justification is achieved. It may be that a person receives the gift of Faith prior to baptism, as with those in Ephesus (Acts 19:1-5). But with infants, who cannot have Faith of their own (save for Our Lady*), rely entirely upon baptism to receive the gift of Faith.
St. Augustine writes:
"Now believing is nothing else than having faith; and accordingly, when, on behalf of an infant as yet incapable of exercising faith, the answer is given that he believes, this answer means that he has faith because of the sacrament of faith, and in like manner the answer is made that he turns himself to God because of the sacrament of conversion, since the answer itself belongs to the celebration of the sacrament. Thus the apostle says, in regard to this sacrament of Baptism: 'We are buried with Christ by baptism into death.' [Rom 6:4] He does not say, 'We have signified our being buried with Him,' but 'We have been buried with Him.' He has therefore given to the sacrament pertaining to so great a transaction no other name than the word describing the transaction itself.
"Therefore an infant, although he is not yet a believer in the sense of having that faith which includes the consenting will of those who exercise it, nevertheless becomes a believer through the sacrament of that faith. For as it is answered that he believes, so also he is called a believer, not because he assents to the truth by an act of his own judgment, but because he receives the sacrament of that truth." (Ep 98, par. 9-10)
So both through circumcision and baptism, a child receives the gift of faith and through that faith, is justified. It is possible for adults to receive the gift of faith and be justified prior to baptism but here we should also distinguish between an intellectual belief, which lays the groundwork for faith, and faith itself, which is a gift of God and not a simple belief. This is why it is not possible to oppose faith to the Sacrament of Faith, although there are cases in which a person may receive the gift of faith prior to receiving the Sacrament. It also may happen a person receives baptism but does not receive the gift of faith because they reject it through disbelief and thus the person is not justified. (ST, IIIa, Q.69, A.9, resp. -- http://bit.ly/1h7gnDH)
Between circumcision and baptism, baptism is the greater Sacrament because it not only remits original and actual sins and incorporates a person into the body of the faithful but also remits all punishments due to sin (ST, IIIa, Q.70, A.4, ad 5 -- http://bit.ly/1h79zGh)
So the water baptism itself remits original Sin, regenerates a baby to be born again, but that ONLY covers past sins, as one MUST co operate with the sacramental grace system in order to make sure they earn and keep merits, as the blood of jesus not sufficient to eterally pardon and cleanse from all sins?
They can mortal sins that undo/overcome the cleansing of the blood of Son of god himself then?