Or do you not know that the unrighteous will not inherit the kingdom of God?"
Settle your own disputes
go to your brother or sister in Christ
It is not often that we hear of a case of where brother's-in-Christ go to court to resolve their differences. However this passage concerns such a situation. Do you resolve it in the government court of law amongst unbelievers, OR do you resolve it in your family of Christ. I pray the situation never arises, but Paul is saying keep it out of court, resolve it brother to brother, forgive each other.