John 6:53 Then Jesus said unto them, Verily, verily, I say unto you, Except ye eat the flesh of the Son of man, and drink his blood, ye have no life in you.
54 Whoso eateth my flesh, and drinketh my blood, hath eternal life; and I will raise him up at the last day.
56 He that eateth my flesh, and drinketh my blood, dwelleth in me, and I in him.
We have about 3 views on this doctrine. One is of Rome and transubstantiation; we have the view that the supper is solely symbolic and then we have the Presbyterian view which is a mix of the last two.
The supper is much more than a symbol. It is communion. In this communion, God meets with His people in a way that he does not do otherwise. It is a vertical connection directly to Heaven. Consider how a cell phone works. When we partake of the sacrament, we bring to light Jacob’s ladder. When we eat of the bread, we are eating of the flesh of Christ. Yes, it stays bread, but none the less. When we drink of the wine, we are drinking the blood of Christ. It is surely mysterious. Believers are spiritually nourished when we partake. We grow in our faith.
WCF ch 29
I. Our Lord Jesus, in the night wherein he was betrayed, instituted the sacrament of his body and blood, called the Lord’s Supper, to be observed in his Church unto the end of the world; for the perpetual remembrance of the sacrifice of himself in his death, the sealing all benefits thereof unto true believers, their spiritual nourishment and growth in him, their further engagement in and to all duties which they owe unto him; and to be a bond and pledge of their communion with him, and with each other, as members of his mystical body.
V. The outward elements in this sacrament, duly set apart to the uses ordained by Christ, have such relation to him crucified, as that truly, yet sacramentally only, they are sometimes called by the name of the things they represent, to wit, the body and blood of Christ; albeit, in substance and nature, they still remain truly, and only, bread and wine, as they were before.
VII. Worthy receivers, outwardly partaking of the visible elements in this sacrament, do then also inwardly by faith, really and indeed, yet not carnally and corporally, but spiritually, receive and feed upon Christ crucified, and all benefits of his death: the body and blood of Christ being then not corporally or carnally in, with, or under the bread and wine; yet as really, but spiritually, present to the faith of believers in that ordinance, as the elements themselves are to their outward senses.