And he took the cup and gave thanks, and gave it to them saying, "Drink from it, all of you, for this is my blood of the new covenant, which is shed for many for the forgiveness of sins." (Matt 26:27-28)Whenever we receive the Lord's supper, we receive Christ's pledge that our sins are forgiven. Many times we comfort ourselves with this -- that our sins are forgiven, that here in communion we have Christ's pledge sealed with his own body and blood.
So how is it possible for our feuds to continue? Haven't we all come together to take the same bread and wine? Haven't we all shared the same cup, and raised the toast of "forgiveness"? When we celebrate our own forgiveness, we celebrate our brothers' and sisters' forgiveness as well. Everyone who has taken that bread and wine has shared in the forgiveness of sins. Do we still keep a record of their wrongs, when God has forgiven them? I think we must be offending against Christ, to come for our own forgiveness based on his sacrifice, and refuse to forgive our brothers who have come for that same forgiveness.
The Lord's Supper is not just a fresh start for each of us personally. It is also a fresh start for all those in Christ. There is a power in that, that all the evil that has worked throughout a congregation might be undone by a single worship service. By coming together just once fully embracing what God has done not just for one of us, but for all of us together, layers on layers of resentment can be washed away in a single morning. It must be a grave insult to evil that all its work can be undone so easily, by bread and wine and Christ's forgiveness. Evil's power must be nothing next to God's, that years of bitterness and strife can be undone in a single hour.