'If we say that we have no sin, we deceive ourselves, and the truth is not in us. If we confess our sins, [God] is faithful and just to forgive us our sins and to cleanse us from all unrighteousness.'
- 1st John 1: 8-9
In baptism, our old, sinful self dies, and we rise from the water born again as a new creation, pure, fully in Christ, and free from sin. We are clothed in a white garment and admonished to keep it pure and spotless all the days of our life.
Yet, for most of us, we only need examine a single hour of our lives to know that we do not remain sinless for very long. We sin. We allow and even invite things into our lives that are contrary to the life in Christ. We hurt ourselves and others around us with our thoughts, our words, and our deeds, and so hinder our growth into the likeness of God - the very purpose of the Christian life. In so doing, we harm the bonds of communion that exist between us and God, and between us and our sisters and brothers in the fellowship of Christ's Body, the Church.
However, God, Who is merciful and just, is always ready to forgive, and has granted to his priests the ability to extend this forgiveness to all who earnestly wish to turn away from their sin and return to Him. So we can come to Confession and return to our baptismal state.
This does not mean, though, that Confession is to be thought of as a "get out of jail free" card that we can keep stashed away to use at a convenient time when our sinful lives catch up with us, only for us then to return to the same way of life. This would be a mockery of the sacrament and of the grace of God. Repentance is the English word for what in the Greek of the New Testament is "metania", which literally refers to a conversion, a turning around. We are to examine our lives and our hearts prior to each confession, and identify those things that hinder our life in Christ. A good preparation for confession may be found here. When we approach the sacrament and stand before the image of the Saviour, we are to do so with the intention of leaving behind us those things that separate us from the fullness of life in Christ.
In the early Church, the practice existed of people confessing their sins before the whole Christian community. Today, this is no longer practised and the priest (or another confessor) acts as a single witness. Still, the act of confessing the things of which we may be most ashamed in front of another person can be terrifying. However, once we move past the initial fear, we realise that having to say the words in the hearing of another person has a dual benefit. It forces us to confront within ourselves the reality and the shame of what we have done, which can be so easily avoided in private prayer. This helps to bring about true repentance. The second benefit is that it restores our sense of belonging and trust in the Christian community of which we are part, and re-forms our relationship with the community and particularly with the priest not as one where we must be seen to be pious and respectable but where we become more honest and are no longer ashamed for it to be known that we have failings. This makes us less fearful of our next confession, and we might even begin to find that we look forward to being able to confess our sins, and hearing the words, 'and now, having no more care for the sins you have confessed, go in peace'.