What is sin?

In the Bible study I go to on Wednesday nights, we've been talking about sin and I wanted to share some of what we've talked about. The group made a working definition for what we believe sin to be:

Sin is a willful or unwillful act or state of being which is inherent in humanity that distances us from God, neighbor and environment; which God is forgiving, and healing in conjunction with humanity through the mystery of grace in Jesus Christ.

In my education, I have been taught that sin is simply separation from God. This doesn't really tell us everything that sin is and can be. We continued our discussion last night on corporate sin. There is this cycle of sin that occurs between the individual and the institution of the Church. It's the chicken and the egg situation. "Self perpetuating sin." So how do we end this cycle of sin? Take out the institution? We would just replace that institution with another.Some possibilities for solutions:
1. Separation: separate the institution. (only, we can't because we end up replacing with something else [another institution], so it's not very helpful to us)
2. Liberal: Change the instution? (only, we probably can't do this)
3. Conservation: create individuals who are as good as they can possibly be in order to keep the cycle from continuing to the institution (no matter how good a bible study is, it doesn't mean people will change)
4. God.

He's our only hope. It sounds cliche but it's the truth: Our only hope for overcoming sin is God.