Penance, confession

...God's forgiveness and reconciliation with the Church, which are expressed and accomplished liturgically by the sacrament of Penance and Reconciliation.Catechism of the Catholic Church 1440

It is through the sacrament of Penance that the baptized can be reconciled with God and with the Church:

This sacrament of Penance is necessary for salvation for those who have fallen after Baptism, just as Baptism is necessary for salvation for those who have not yet been reborn.Catechism of the Catholic Church 1440

The Fourth Lateran Council (1215) required that all Roman Catholics receive the sacrament of penance at least once a year. Confession (called Penance and Reconciliation) involves the sinner making a confession before a Catholic priest, who Catholics believe God has given the power to forgive sins, for the mortal sins¹ he or she has committed. Long story short, the sinner is thus absolved of their sins. Attrition (repentance due to fear of punishment) is an acceptable part of the sacrament of penance. If penance does not occur, Romanists believe that "perfect contrition" (true love of God and sorrow for sins committed) may suffice, though the Council of Trent decided that such contrition was not sufficient by itself. The process is as follows:

1. The sinner examines himself and prays to the Trinity
2. The sinner enters the confessional and gives the Sign of the Cross
3. The priest may read a passage of Scripture
4. The sinner says a variation of, "Forgive me, father, for I have sinned. It has been ___ years since my last confession."
5. The sinner confesses his sins, and my end in a semi-formal statement, such as, "I am sorry for these and for all the sins of my past life."
6. The priest issues some words of guidance/encouragement, then assigns the required penance. Penance may include recitation of the Rosary, meditation on Scripture, or other indulgences.
7. The sinner recites the Act of Contrition.²
8. The priest prays a prayer of Absolution.³
9. The sinner leaves and performs his acts of penance.

The Catholic justification

The primary justification given for penance is the citation of John 20:22-23. After the resurrection, Jesus appeared to the disciples:

22 And after he said this, he breathed on them and said, "Receive the Holy Spirit. 23 If you forgive anyone's sins, they are forgiven; if you retain anyone's sins, they are retained."John 20:22-23

The other justifications will be given in the following refutation section.

Refuting the heresy

In general, the sacrament of penance is heresy against the full atonement of Christ, the Biblical doctrine and truth of salvation by grace through faith in Christ alone, and the universal priesthood of believers.

John 20:22-23

The Roman Catholic church, somewhat in contradiction to itself, believes that no man actually has the power to forgive sins, but that God gives men authority to forgive sins. This leads them no way to interpret this verse to give special authority to the Catholic priest, since it is God who forgives sins anyway, and thus the Catholic might as well confess to a prostitute on the street for all it matters. There is no historical record of the apostles forgiving anyone's sins, but rather of them telling people to seek forgiveness from God. Ignoring this, the Romanist would still have to show how Christ's statement to the apostles applies to the Roman priesthood.

Note also that this verse, if interpreted to mean that man has the authority to forgive sins, allows man to forgive any sins he wishes (If you forgive anyone's sins), and that man can retain any sins he wishes, regardless of the sinner's church membership, stance before God, repentance, etc. In fact, the Romanist interpretation would completely do away with the need for sacraments. Clearly the Romanist interpretation can't possibly be true. So what does the verse actually mean?

Whatever its actual meaning, it must be accordance with the rest of Scripture, and so it must be understood that forgiveness comes from God by grace for those who believe in Christ. So while the exact meaning of John 20:23 may be unclear, its limitations are not.

Matthew 9:2-8

Again, Scripture clearly teaches that God alone has the ability to forgive sins. Also remember that giving men the authority to forgive sins would negate Catholic dogma on other matters (such as baptism and penance).

If the authority mentioned in Matthew 9:8 is the authority to forgive sins, then it is speaking of a misunderstanding the onlookers had. Jesus was accused of blasphemy for claiming, as a man, to have the power to forgive sins. It indeed is blasphemy for a man to claim the authority to forgive sins, but it is not blasphemy for God to forgive sins (and Jesus surely is God). However, the miracle Jesus performed may have been understood as proof that man can forgive sins, rather than understood as proof that Jesus is God, as is the proper understanding.

It is possible that the authority mentioned is simply the authority and power to heal, as Jesus miraculously did.

Lastly, note that Jesus does not say that man can forgive sins, but specifically refers to His own ability to forgive sins, using the divine title "Son of Man" from Daniel's vision. Interpreting Matthew 9 as saying that man has the authority to forgive sins, ontop of its many other problems, would mean that man already had authority to forgive sins before Christ breathed on His disciples in John 20. The Catholic has to decide which verse he wants to use to make his case, since their interpretation of Matthew 9 contradicts their interpretation of John 20.

2 Corinthians 5:17-20

I'm not sure why a Catholic would even bothering mentioned these verses in defense of confession/the priest's ability to forgive sins. If anything, these verses define such authority as nothing more than pleading with one to be reconciled to God. Verse 21 makes it clear how we are reconciled--God's own righteousness, not our own, is applied to us. It is not power to forgive sins that God gives men, but the message of reconciliation (v19).

Notes

1Grave sins are those which involve 1) a grave matter, 2) full knowledge of both the sin and its gravity, and 3) deliberate and complete consent. Romanists believe that, unlike venial sins, mortal sins that are left undealt with result in condemnation.

2 O my God, I am heartily sorry
for having offended Thee,
and I detest all my sins,
because of thy just punishment,
but most of all because they
offend Thee, my God,
Who are all-good and deserving
of all my love.
I firmly resolve, with the help
of Thy grace to confess my sins,
to do penance
and to amend my life. Amen.

3 Essential words in green:
God, the Father of mercies, through the death and resurrection of his Son has reconciled the world to himself and sent the Holy Spirit among us for the forgiveness of sins; through the ministry of the Church may God give you pardon and peace, and I absolve you from your sins in the name of the Father, and of the Son, and of the Holy Spirit. Amen.