"The principal object of the Lord’s supper was to remind Christians of Christ’s death for sinners. In appointing the Lord’s supper, Jesus distinctly tells His disciples that they were to do what they did, “in remembrance of him.” In one word, the Lord’s supper is not a sacrifice. It is eminently a commemorative ordinance.
The bread that the believer eats, at the Lord’s table, is intended to remind him of Christ’s body given to death on the cross for his sins. The wine that he drinks is intended to remind him of Christ’s blood shed to make atonement for his transgressions. The whole ordinance was meant to keep fresh in his memory the sacrifice of Christ on the cross, and the satisfaction which that sacrifice made for the sin of the world. The two elements of bread and wine were intended to preach Christ crucified as our substitute under lively emblems. They were to be a visible sermon, appealing to the believer’s senses, and teaching the old foundation-truth of the Gospel, that Christ’s death on the cross is the life of man’s soul."
~ J.C. Ryle