All of us have become members of Christ. How do you fail to sin against Christ when you sin against a member of Christ? Thus, if you are offering your gift at the altar and there remember that your brother or sister has anything against you, leave your gift before the altar.
God seeks you rather than your gift. Christ seeks the one whom He has redeemed by His Blood rather than what you have found in your storeroom.
St. Augustine 354 - 430