Communion

What is communion? When council meeting and communion come around, twice a year for us, I always have some questions. We practice a close communion not to be confused with closed communion. Close communion is when you can participate if you have made prior arrangements. Should participation in this service be solely based on my relationship with God? If a partake unworthily it is between God and I? Or should my participation be based on accountability to others and God? I wonder if we are correct in our approach. The argument against open communion stems from how little we know an individual. If he/she is living in sin and we commune with them we would be doing an unwise thing. Why? Isn't their sin between them and the Lord? I realize there needs to be forgiveness and accountability to the church body. Should this rule out letting people we do not know participate?