In Leviticus 5:5-6, we read, “then whoever is guilty in any of these cases shall confess that sin that he has incurred, and as his sin offering for the sin he has committed he shall bring to the Lord a female animal from the flock, a ewe lamb or a she-goat. The priest shall then make atonement for his sin.”
And in Numbers we read, “And the Lord said to Moses, “Say to the people of Israel, When a man or woman commits any of the sins that men commit by breaking faith with the Lord, and that person is guilty, he shall confess his sin which he has committed; and he shall make full restitution for his wrong, adding a fifth to it, and giving it to him to whom he did the wrong. But if the man has no kinsmen to whom restitution may be made for the wrong, the restitution for the wrong shall go for the priest, in addition to the ram of atonement with which atonement is made for him. And every offering, all the holy things of the people of Israel, which they bring to the priest, shall be his; and every man's holy things shall be his; whatever any man gives to the priest shall be his.”” (Nm 5:5-10)
So, what are we seeing in the OT? We see 1) confession of the sin committed, 2) a form of penance, specifically in these cases a “sin offering” AND “restitution” for the sin and 3) the person is NOT to go straight to God, but through a priest. God set it up so that they were to go through a priest for confessing their sins, and this going through a priest is a foreshadowing of things to come (cf. Hb 10:1, Mt 5:16-18). So, what do we see in the New Testament?
“...and they were baptized by him [John the Baptist] in the river Jordan, confessing their sins” (Mt 3:6). Okay, so it looks like the Jews are still observing the confession of sins to a man...whom they believe is a prophet...a man whom God works through. Let's look further, in Mt 9:2-8, along with Mk 2:7, which is the same story.
Jesus tells a paralytic to “take heart”, that his “sins are forgiven” (Mt 9:2). But what objection do we hear? “This man is blaspheming” (Mt 9:3, Mk 2:7), “who can forgive sin but God alone?” (Mk2:7). But we know that it is the Scribes that make this objection, and as Christ points out, while it is true that God alone forgives sins, this statement betrays a limited understanding of God's Power. Jesus shows them the shallowness of their words so, “that you may know the Son of Man has authority on earth to forgive sins” (Mt 9:6). And then what does Scripture tell us? “When the crowds saw it, they were afraid, and glorified God, who had given such authority to men” (Mt 9:8). It says, “to MEN”, plural...not just to “a Man” (Jesus) but to MEN. But maybe this is just a typographical error in the Scriptures. Let's look at some other passages in the Scripture to see if it clears this up for us.
In 1John 1:9, we read, “If we confess our sins, he is faithful and just, and will forgive our sins and cleanse us from all unrighteousness.” Okay, so this sounds a little more palatable for those who say we just go straight to God, and God alone...or does it? Does it say HOW we confess our sins? Does it say to go straight to God, and God ALONE? No, it doesn't say that. Maybe there are other passages we can look at to get some better instructions on this.
“Many also of those who were now believers came, confessing and divulging their practices” (Acts 19:18). Oh...this makes it sound like these new believers were confessing their sins to the Apostles or other leaders in Christ's Church. Can that be right? Let's look at James chapter 5. “Is any one among you suffering? Let him pray. Is any cheerful? Let him sing praise. Is any among you sick? Let him call for the elders of the church, and let them pray over him, anointing him with oil in the name of the Lord; and the prayer of faith will save the sick man, and the Lord will raise him up [say...that sounds like the Catholic Sacrament called “Anointing of the Sick”!]; and if he has committed sins, he will be forgiven” (James 5:13-15). Wait, is it saying that he will be forgiven because of the prayers of the presbyters/elders? “Therefore confess your sins to one another, and pray for one another, that you may be healed. The prayer of a righteous man has great power in its effects” (James 5:16). Yep...that's exactly what it's saying. But do we confess to just ANYONE? Or should we confess to someone to whom Christ has given the authority to forgive sins? I mean, sure, God alone forgives sins...and so far we see that God has set things up so that we go to a priest for this, but did He REALLY give such authority to certain men??
“Jesus said to them again, “Peace be with you. As the Father has sent me, even I send you” (Jn 20:21). Okay, how did the Father send Christ? He sent Him with the power to forgive sins. And now Christ is essentially telling His Apostles that they are to do likewise... as the Father has sent Christ, so Christ sends the Apostles. But surely that doesn't really mean forgiving sins, right? “And when He had said this, He breathed on them, and said to them, “Receive the Holy Spirit. If you forgive the sins of any, they are forgiven; if you retain the sins of any, they are retained”” (John 20:22-23). Yep, Christ could not have been more explicitly clear. Christ has set it up so that we are to go through a Priest for the confession of our sins...in a more profound way which is the revealed “good thing to come” which was shadowed in the old law. An interesting note here also is that “He breathed on them”. How many times in the entirety of Scripture does God “breathe” on anyone? I can only think of one other instance where He does this...and it's in Genesis.
We can also look at 2Cor 5:17-20: “Therefore, if any one is in Christ, he is a new creation; the old has passed away, behold, the new has come. All this is from God, who through Christ reconciled us to himself and gave us the ministry of reconciliation; that is, God was in Christ reconciling the world to Himself, not counting their trespasses against them, and entrusting to us the message of reconciliation. So we are ambassadors for Christ, God making His appeal through us. We beseech you on behalf of Christ, be reconciled to God.” Yep...that, in context of the other several passages from Scripture we have looked at so far, sounds EXACTLY like the Catholic teaching on the Sacrament of Reconciliation.
In Mt 18:18, Christ tells His Apostles, “whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosed in heaven”. Here Christ gives the other Apostles a share in the authority He had already given to Peter in Mt 16:19, “I will give you [Peter] the keys to the kingdom of heaven, and whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosed in heaven”. Notice Christ says “whatever” you bind/loose. “Whatever” means...well....whatever...no implied restrictions there that I can see. This is a judiciary power of binding and loosing, coupled with the same power we saw in John 20:21-23 to forgive or retain sins, given to the pastors of Christ's Church by Christ Himself. The obligation of auricular confession to a Priest is based upon these.
So, in fulfilling the old law...revealing the "good thing" that was to come, which was only shadowed in the old (cf. Hb 10:1, Mt 5:16-18), Christ has given authority to the leaders in His Church, and the new version of the old looks like this: 1) confessing of the sins committed, 2) to a Priest, through whom Christ has chosen to act, in a ministry...a Sacrament...through which Christ has chosen to impart His Grace to us (cf. 2Cor 5:17-20), 3) involving a penance, by which we pay restitution for the temporal damage inflicted to ourselves and others...while the actual sin itself is forgiven (or retained)...by someone whom Christ has given such authority to (cf. Jn 20:21-23).