1 Corinthians 5:1-13
Healthy church requires honesty. Paul writes a tough chapter on the overall health of the church. He brings up an example of a member of the church who is living a sexually immoral lifestyle. He makes the point that as a body of believers, if one part of the body is living in outright sin, it is unhealthy for the rest of the body. The church of Corinth was ignoring, if not even boasting in this man’s presence as if all was right and good in the community. 
As a body of believers we are asked to call sin for what it is within other believers so as to restore them back to truth. This way the entire body remains healthy. One of the many reasons God created us to be in community is so we are able to keep one another healthy in the body of Christ. 
Paul reminds us that it is important and healthy to openly rebuke, as well as encourage other believers with truth, not just opinion. He makes it very clear we cannot call out non believers in their sin. They can not receive that judgement from us, only God can do that. Paul writes in Colossians 4:6 we are to walk in wisdom towards outsiders, always gracious and seasoned with salt. We are to answer each non believer with the wisdom of the Holy Spirit and the example of love and grace Jesus has shown us. 
To create and foster a healthy community it is important to challenge each member of the body. As Paul said back in 3:6-9, we are to water others, so God can grow them. In encouragement and in rebuke in the midst of sin, God can grow each member. Each member is also called to treat others outside of the body with the love of Christ, just as He showed us before we became part of the body.