Orthodox have confession as a sacrament although the priest is more of spiritual guide then anything else.
Anglicans also have a form of confession. For most it involves a prayer and a moment of inward confessing during the service, but they also have a private form of confession in some sects including Anglo-Catholics (which incidentally some are seeking to join the Church similar to the Eastern rites). Outside of Anglo-Catholics, private confession is not mandated.
Presbyterian USA also has a prayer during their worship service for confession.
Lutherans also have a form of confession like Anglicans and Catholics where it is part of the worship service and can be private. They also believe that confession should be two part: confession and absolution and they believe it to be a Biblical mandate (which I will explain in more detail later).
Mormons also have confession directly to God and through their priesthood.
Generally speaking, most main stream Protestants believe that confession or asking forgiveness for sins should be done directly with God alone and without a witness. Although if a person is coming back to his or her church, some denominations especially in Evangelical circles have public confession in front of the congregation or private confession with the minister. Public confessions usually involve grave sins and are often referred to as "altar calls." Although altar calls can simply be part of a conversion process as well.
I talk about all this because there seems to be some view amongst many Protestant brothers and sisters that confession is something that only Catholics do. So I'd like to talk about some of the things that are a bit different and why we confess or ask forgiveness for sins this way.
Let's start off with a few misconceptions that seem to be perpetuated by movies and the like
1) No priest has the power to forgive sins. That's up to God and God alone. So why a priest at all? James 5:16 Therefore, confess your sins to one another and pray for one another, that you may be healed. The fervent prayer of a righteous person is very powerful. Note that Lutherans and Anglicans also view this to mean that you must confess your sins to a person. So too do a number of other denominations hence altar calls. There is a difference among denomination as to the frequency. Catholic believe that is important to confess regularly or suffer death with the stain of sin on your soul. Sin, in the Catholic view, is a person's choice to disobey God and turn away from God. So in order to reach heaven, you want to be on your best behavior and on good terms with God. But I don't think anyone would disagree about there being a judgment day.
2) Man, the Catholic church, etc. did not institute confession. Rather Jesus himself did. It was Jesus who gave the authority to forgive sins and give absolution to those who are truly sorrowful to his disciples. Where do I get this idea? John 20:22-23 And when he had said this, he breathed on them [his disciples] and said to them, "Receive the Holy Spirit. Whose sins you forgive are forgiven them, and whose sins you retain are retained."
3) You can't simply walk into a confessional booth, say you've sinned, and say a few prayers in order to be forgiven. You have to really be sorrowful and truly repentant in order to be forgiven. Otherwise you're still in a state of sin and you've just committed a new one by not respecting the sacrament that Jesus set up.
4) You can't go into confession expecting to wipe the slate clean but yet continue as before. If you're confessing because you co-habitat (for example) then a truly repentant person would move out. A priest would most likely advise doing so and would offer suggests on how to find temporary shelter until secure lodging is in place. Catholics don't get free passes anymore than Protestants do simply because we go to confession.
5) Conversely, some people find confession to be too harsh and therefore such "punishments" are not necessary since Christ is a loving father. But then you need to read the Bible verses listed in both 1 and 2.
6) You might be thinking. Okay I see your point about confession, but why a penance when Jesus died for our sins. Yes, Catholics believe that Jesus died for us and no matter what we do we will never be able to repay our debt. However, the point of a penance is to reconcile ourselves with God. You see sin divides us from God. It is a turning away from God. When you turn away from a friend over a disagreement but then decide to reconcile later, you must do something in order to be reconciled otherwise it's fruitless. You either have to call them or e-mail or speak to them in person and start over. So too is penance. Most people think of penance as a punishment, but that's just because they come from the same root word. Penance isn't the same as a punishment. It's more like a reconciliation. It's telling God that "I screwed up and I'll try harder not to in the future please forgive me for being such a butt head."
You can see why I say it's reconciliation because in the most common prayer that people use before, during, or after confession it basically outlines this.
The Act of Contrition
Other prayers that are commonly used as a penance are the Our Father which says "forgive us our sins (trespasses, debts) as we forgive those who sinned against us" and the Hail Mary because it too talks about sin "Holy Mary, Mother of God, pray for us sinners now and at the hour of our death". So priests don't typically assign prayers willy nilly. Their intent is for us to reconcile ourselves to God and ask for forgiveness and aid to do better.
Penance also makes amends to the person(s) we have sinned against and therefore hurt our relationship with God. For example, if a person steals something, their penance would be to return the item. Priests typically will assign you prayers to reconcile yourself to the community and if it's something that needs to be addressed to specific persons, you will most likely have to do so also (like the stealing thing). Catholics believe that we are a community of believers, the Body of Christ, therefore what we do does hurt others. You can see this in our prayer used during Mass.
Confiteor (I Confess)
- I confess to almighty God,
- and to you, my brothers and sisters,
- that I have sinned through my own fault,
- in my thoughts and in my words,
- in what I have done, and in what I have failed to do;
- and I ask Blessed Mary, ever virgin,
- all the angels and saints,
- and you, my brothers and sisters, to pray for me
- to the Lord our God.
*Note that we ask the BVM and angels and saints and our fellow parishioners to pray for us. And it's to God. There's a common misconception that we worship the BVM etc. This isn't true. Catholics believe that there is a congregation on earth and in heaven and that we are one and the same so we can ask dead people to pray for us just like live ones. Why, well, that's another blog post.
Hope that this has demystified confession a little bit. BTW the Hail Mary is in the Bible too. Luke 1:28. One of my confirmation students didn't realize that until we watched the Nativity. So read your Bible! And sign-up to take the Bible/Catechism challenge, you'll learn a lot.