Jesus reclined with the twelve and said:"This is My body which is given for you; do this in remembrance of Me." Likewise He also took the cup after supper, saying, "This cup is the new covenant in My blood, which is shed for you. (Luke 22:19-20)
In doing and saying this Jesus established the Lord’s supper and each time we take communion together, we remember His death until He comes. But, the bread and wine are symbols of the physical. They are not the literal body and blood. In John 6:63 we read: It is the Spirit who gives life; the flesh profits nothing. The words that I speak to you are spirit, and they are life.
The disciples were stumbled by Jesus teaching concerning His body and blood and He says to them: “It is the Spirit who gives life..” Jesus’ words were Spirit and life and if you breath His word in, you will have life. Jesus spoke of Spiritual things but most of the disciples could only hear of physical things. They didn’t have the faith to believe. In order to participate in the physical reality of Jesus death and resurrection we must believe in the Spiritual efficacy of His death and resurrection. God received the sacrifice of Jesus as payment for Sin and then raised Him up from the dead. In order to benefit from this we must believe in this.
The symbols remind us of what Christ did for us. But, we must not put faith in the symbols but have faith in the literal Jesus who died and rose again. Ours is not a religion of ritual and repetition but one of faith and life. We take the bread and wine as symbols in remembrance of the physical sacrifice of Christ on the cross.