Augustine wrote The Confessions to God, not to us, although much of the book touched me like nothing else I've ever read outside of the Bible. He had a good idea - confession is Biblical after all:
I acknowledged my sin to you, and I did not cover my iniquity; I said, "I will confess my transgressions to the LORD," and you forgave the iniquity of my sin. (Psalms 32:5)
Whoever conceals his transgressions will not prosper, but he who confesses and forsakes them will obtain mercy. (Proverbs 28:13)
Therefore, confess your sins to one another and pray for one another, that you may be healed. The prayer of a righteous person has great power as it is working. (James 5:16)
If we say we have no sin, we deceive ourselves, and the truth is not in us. If we confess our sins, he is faithful and just to forgive us our sins and to cleanse us from all unrighteousness. If we say we have not sinned, we make him a liar, and his word is not in us. (1 John 1:8-10)
Most of the passages that refer to confession throughout the Bible refer to confession to God. James 5 was the only passage that I found directly relating confession of our sins to one another. In that passage it is so that others can pray for you. It is notably not so that others can act concerned and tell all of their friends the great tidbit they learned - that would be gossip of course and there are verses about that as well. I say that latter part because I think that gossip is one of the great unacknowledged evils and I find that some people who want more confession one to another seem to want it for the salacious information rather than to be helpful to each other in prayer. Any grocery aisle today will attest to the immense human thirst for salacious information on other individuals so denying that this motivation exists is nonsense. I think that one of the reasons that gossip and slander is so evil is that it destroys confession and therefore it hinders our prayers for each other (because so much that goes on we never know about). Nobody wants to say anything to anybody because we cannot acknowledge that we have this evil tendency and so we destroy our brothers and sisters with our tongues after we discover some juicy tidbit that was told to us in confidence or which we discovered from some other gossip when what we really ought to be doing is covering their sin and taking it up to God on their behalf. Acting concerned when you spread it to another person is no substitute for love, either. Francis of Sales in Introduction to the Devout Life discussed this like so:
Those who slander others with an affectation of good will, or with dishonest pretences of friendliness, are the most spiteful and evil of all. They will profess that they love their victim, and that in many ways he is an excellent man, but all the same, truth must be told, and he was very wrong in such a matter; or that such and such a woman is very virtuous generally, but and so on. Do you not see through the artifice? He who draws a bow draws the arrow as close as he can to himself, but it is only to let it fly more forcibly; and so such slanderers appear to be withholding their evil-speaking, but it is only to let it fly with surer aim and go deeper into the listeners’ minds.
We have such a problem with this and we try to counteract the destruction of confession in the churches, not by acknowledging and working against slander and gossip, those pests at the root of the tree, but rather by simply pushing everyone harder to confess, confess, confess. This will do no good. We have to get love correct and confession will come from it. That connection is important. The gossip and slanderer does not love the object of their tales, they love the sin they are committing. I'll tell you this, I have confessed all of my struggles and sins to my wife - she knows everything about me, all that I struggle with and all of my failures but there is a reason for this: she prays to God for me, of this I am certain, but she does not take my confessions to her friends and I don't take hers to mine, so I trust her in everything. I have no fear with confessing to her because I know this about her (it is one of the main reasons I fell in love with her). I tell you this because if we were all like this with each other - that is, if we all went to God with each other's sins rather than each other - we would find confession comes naturally as a result.