Catholics need to come to the understanding that Jesus died once for our sins and said "It is finished". What we do in communion is remember what He already did for us. Jesus has healed scars, not wounds, dripping with blood.
The first thing I thought of was when Jesus, in His glorified body after the resurrection, appeared before the disciples. He told Thomas to touch and feel the nail scars in His hands and to believe that He was truly there with them. Thomas fell down before Him and exclaimed, "My Lord and my God!". I think in heaven we will always be in the presence of Jesus our Savior and He will always have those scars on His feet and hands as a reminder to us of the great sacrifice He made on our behalf and we will never forget that we are there not because of what we did for Him, but what He did for us.
The observance of the Lord's Supper is a reminder to us while we are still here, but in heaven we will have Him before us as that reminder for eternity. The partaking of the bread and wine together with the body of Christ (fellow believers) was instituted just as all the other observances and memorials were - to keep things ever before us - so we don't ever forget. When the Israelites encountered amazing things on their journey through the wilderness, they stopped along the way and built memorials to commemorate the miracles the Lord provided along the way. Just as God says he will never forget us, we are given these things so we will never forget Him.