Best answers so far:

Yeah, I don’t know all the reasons Jesus set it up that way, but for me I am so thankful because when the priest hold up his hands over me and I hear those words of absolution, they are the most beautiful words in the world! Giving the power to forgive sins was one of the first things Jesus talked about after He rose from the dead. Do you remember the story on the night of the resurrection when the Apostles were hunkered down in the upper room and Jesus appeared to them? He said “Peace be with you” and them breathed the Holy Spirit on them and said “Receive the Holy Spirit, whose sins you forgive are forgiven and whose sins you retain are retained” Jesus gave these ordinary men the authority to forgive sins! The Catholic church has passed down that authority through the ages by the laying of hands on bishops and priests. I think Jesus wants us to humble ourselves and have that face to face encounter with Him acting thru the priest to experience His mercy, love, and healing. It is an incredible gift that He left the Church He founded.
– David T

When asked why confess to a priest, answer because the Bible tells us to do so. Jesus’ grace and mercy are freely given to his Church. When asked why not pray directly to God, answer because Jesus established it that way. Jesus is the one mediator between God and men for our salvation. Jesus established a church to sub-mediator Christ’s salvation to the world since He has ascended to the right hand of the Father.
If asked why doesn’t one just confess directly to God. Answer we already do and it is normative just like all Protestants do naturally. However, in 2 Cor 5:15, James 5, and John 20:19f Christ directly gives authority to continue His ministry of reconciliation by pronouncing sins forgiven especially serious sins. Therefore, we are following Christ. Catholics are encouraged to confess lesser sins to a priest as well.
Protestants are ‘sola Scriptura’ and many are unaware that priestly confession is in the Bible. If you explain John 20 in the Bible to them it normally brings the conversation to a close. This is because they believe everything in the Bible and are stunned to realize it is in the Bible.
If a Catholic commits a serious sin this results in a loss of salvation. But after one repents, regains salvation. However, a Catholic is then required to confess this serious sin to the church through the priest. If one dies after repentance, but before getting to the sacrament of reconciliation, they will be saved providing they had the intention to obey the law of the church and go to reconciliation.
– Clarence B

I would say Jesus commanded the apostles to do it; and the Bishops/priests are a direct line of succession from the apostles. Therefore, we are commanded by Jesus to confess to a priest. See John 20:21-23
– Suzanne C

Probably something about how Christ (aka God A.K.A. the Truth) established the Sacrament through His Apostles and their successors (and their assistants, the priests) to be a major avenue of encountering and receiving the Mercy of God especially for grave sins.
– Allison A

We don’t confess to a priest instead of God. That is what Jesus asked us to do. When you confess to a priest you are being obedient to Jesus (who is God) and the priest is there by the authority (in persona Christi) and person of Christ. Plus you should confess often to God otherwise and be sorry for your sins so that he can heal us. Scripture tells us it is a good and holy thing to confess to one another. It will heal us. People will go to someone like Benny Hinn but not to a priest who has more power to heal all the very ills of our soul through the power of the Holy Spirit. Such an amazing gift that few find.
– Carol K

Christ, the High Priest of the New Covenant, ordained the apostles to continue His priestly mission. James 5:14-16, (14) “Is any among you sick? Let him bring in the presbyters (priests) of the church, and let them pray over him, anointing him with oil in the name of the Lord; (15) and the prayer of faith will save the sick man, and the Lord will raise him up; and if he be in sins, they will be forgiven him. (16) Confess, therefore, your sins to one another, and pray for one another, that you may be saved. For the unceasing prayer of a just man is of great avail.”
St. James taught us that we must go to the “presbyters”, and not to just anyone, to receive the “anointing”, and the remission of sins. First, he told us to go to the presbyters, or priests, in verse 14. Verse 16 continues with the word “therefore”, so that word is a conjunction that connects verse 16 back to verses 14 and 15. It is the priests to whom St. James told us to confess our sins.
Why do we go to confession? What is the real reason?
We go to meet Christ…
– Arnesh D

When you sin, you don’t just sin against God, you also sin against the Church. You are not confessing to a priest instead of God. You are confessing to God through the priest and the priest represents the whole Church. And he is also Christ personified.
– Kirsten B

Because Jesus says so! Let’s start with Mark 2 when Jesus heals a paralytic. Jesus sees the faith of the friends of the paralytic and says, “My son, your sins are forgiven.” The scribes were then questioning in their hearts how a man could do this. That would be blasphemy. Jesus perceiving that they “thought” this said to them, “Why do you question thus in your hearts? Which is easier to say to the paralytic, ‘Your sins are forgiven,’ or to say, ‘Rise, take up your pallet and walk’? But that you may know that the Son of man has authority on earth to forgive sins? he said to the paralytic – “I say to you, rise, take up your pallet and go home.”
They were amazed that a man had been given power to forgive sins.
– Barbara M

God knows our humanity needs to say our sins out loud and to hear we are forgiven in person. That’s why God gave us Priests in the first place. Instead of the Old Testament sacrificial atonement for our sins, we can now ask God to forgive us directly and then through the Priest (Jesus the Judge by laying on of hands) can absolve us from our sins and reunite us back to his Body the Church.
– Janet D

Our Lord gave the keys to Peter and said what you bind on earth is bound in heaven. What is loosed on earth is loosed in heaven. Peter was the 1st pope and there has been an unbroken line of succession. Through ordination priests are given this power to absolve and reconcile the sinner back in God’s grace.
– Brian F