ut it was after His resurrection that He made known
the efficacy of this sacrament and the source of its power, when He
said (Luke 24:47) that "penance and remission of sins should be
preached in His name unto all nations," after speaking of His Passion
and resurrection. Because it is from the power of the name of Jesus
Christ suffering and rising again that this sacrament is efficacious
unto the remission of sins.

It is therefore evident that this sacrament was suitably instituted
in the New Law.

Reply Obj. 1: It is a natural law that one should repent of the evil
one has done, by grieving for having done it, and by seeking a remedy
for one's grief in some way or other, and also that one should show
some signs of grief, even as the Ninevites did, as we read in John 3.
And yet even in their case there was also something of faith which
they had received through Jonas' preaching, inasmuch as they did
these things in the hope that they would receive pardon from God,
according as we read (John 3:9): "Who can tell if God will turn and
forgive, and will turn away from His fierce anger, and we shall not
perish?" But just as other matters which are of the natural law were
fixed in detail by the institution of the Divine law, as we have
stated in the Second Part (I-II, Q. 91, A. 4; I-II, Q. 95, A. 2; Q.
99), so was it with Penance.

Reply Obj. 2: Things which are of the natural law were determined in
various ways in the Old and in the New Law, in keeping with the
imperfection of the Old, and the perfection of the New. Wherefore
Penance was fixed in a certain way in the Old Law--with regard to
sorrow, that it should be in the heart rather than in external signs,
according to Joel 2:13: "Rend your hearts and not your garments"; and
with regard to seeking a remedy for sorrow, that they should in some
way confess their sins, at least in general, to God's ministers.
Wherefore the Lord said (Lev. 5:17, 18): "If anyone sin through
ignorance . . . he shall offer of the flocks a ram without blemish to
the priest, according to the measure and estimation of the sin, and
the priest shall pray for him, because he did it ignorantly, and it
shall be forgiven him"; since by the very fact of making an offering
for his sin, a man, in a fashion, confessed his sin to the priest.
And accordingly it is written (Prov. 28:13): "He that hideth his
sins, shall not prosper: but he that shall confess, and forsake them,
shall obtain mercy." Not yet, h