key verse: 19
YOUR BODY IS A TEMPLE OF THE HOLY SPIRIT
The Corinthians had a problem with lawsuits between brothers. Paul used this opportunity to explain the Christian identity and its practice.
1. You will judge the world (1-11)
There was conflict among the Corinthians, and some of them brought their cases before unbelievers. They did this because of personal injury, which was a selfish motive. They should have sought an authority within the church to resolve their problems instead of going elsewhere. Yet, there was no one to deal with it. It was a mistake to take their case before people who have no standing in the church, since it would give the world reason to judge the Christian community. It was a subject of shame for the believers. The other problem with pursuing these grievances was that the members forgot their own identity as sinners bought with a price. When someone has a grievance, it's an opportunity to understand the sacrifice and humility of Jesus. Yet the Corinthians didn't want to give up any rights. Thus, they distanced themselves from God's grace. Paul had to re-explain what they had been saved from.
2. Do you not know? (12-20)
Paul said not to be enslaved by anything. This is because Jesus died to free us. Nothing should hinder us, especially sinful desire. Immorality is a sin that enslaves us. It's a sin which degrades one's own body. A Christian should know how precious the body is and reject Gnostic thinking which despises the physical body. Jesus, the Son of God, became flesh in order to save sinful man. The body is given so that we may glorify God in it. In the flesh, the Christian must combat "leavening" every day. First, he must hold fast to the Holy Spirit, the spirit of Jesus. Then, because of physical weakness, he must flee immorality instead of facing it.