The Sacrament of Holy Communion, or the Lord’s Supper, is one of the two sacraments for Reformed Christians. The Reformed view of Communion rejects errors on either side – on the one hand, we reject transubstantiation, the belief that the bread and wine literally change substance into the physical body and blood of Christ, but we also reject memorialism, the belief that Communion is just a remembrance of what Christ did for us, and that Christ is not present in any unique way in the sacrament.
The Reformed view can be called Spiritual Real Presence. Just like Lutherans, Catholics, Anglicans, and the Orthodox, we believe that Christ’s body and blood are “really present” in the Sacrament, but unlike Lutherans and Catholics, we don’t believe they are present in the physical bread and wine. Spiritual Presence doesn’t mean that there’s some spiritual cloud floating around the bread and wine, but that the Holy Spirit communicates Christ’s body and blood to us when we receive the bread and wine. We say this because Communion is for our spiritual, rather than our physical nourishment. It’s not a carnal, physical eating, but a spiritual feeding of Christ’s humanity that makes us more like him. That is what the Bible means when it says Christ lives in us.
We arrive at this view as a result of following Biblical, Chalcedonian Christology. The council of Chalcedon clarified the Biblical doctrine that Christ has two natures, a human nature and a divine nature, which are without mixing, without confusion, without separation, and without division. Because we cannot mix the two natures, we cannot say that Christ’s human nature can be in many places at the same time, since omnipresence is an attribute of His divine nature. In order for Christ’s human nature to be truly human, it must have the same limitations as all other human natures. So to say that Christ’s body and blood can be located in all the places where Communion is celebrated at the same time contradicts this Chalcedonian definition of Christ’s two natures. Instead we say that Christ’s human nature is located in Heaven, but in Communion, the Holy Spirit forms a bond between us and him so that we, by faith, may be lifted up to Heaven with all the saints to feed on the true body and blood of Christ.
The Reformed tradition, following Augustine, defines a Sacrament as a union of the outward sign and the inward reality signified. For Communion, the outward sign is the bread and wine, and the thing signified is Christ’s body and blood. For both Sacraments, Baptism and Communion, one must have faith to receive both the sign and the thing signified in the Sacrament, otherwise, they only receive the outward sign. Unbelievers who take Communion do not receive the body and blood of Christ, because they can only be received with the mouth of faith. Instead, they receive God’s judgment, which is why unbelievers are not to be permitted to take Communion.
For both sacraments, the outward sign isn’t necessary for salvation, but the inward reality signified is, and the inward reality is normally delivered with the sign. As Jesus tells us in John chapter 6, we must eat His flesh and drink His blood to have eternal life. This is because eternal life is us being united with Christ and made more like Him. When the Bible says Christ lives in us, it is because we feed on Him and become more like Him. This process happens through the sacrament of Holy Communion, but it is theoretically possible for this spiritual feeding on Christ to happen outside of the sacrament. Still, we maintain that Communion is necessary for eternal life under ordinary circumstances. Not that it is a requirement in addition to faith in Christ, but that Communion is part of faith in Christ and is only effective by faith.
We must then really receive in the Supper the body and blood of Jesus Christ, since the Lord there represents to us the communion of both. For otherwise what would it mean that we eat the bread and drink the wine as a sign that his flesh is our food and his blood our drink, if he gave only bread and wine and left the spiritual reality behind? Would it not be under false colors that he had instituted this mystery? We have then to confess that if the representation which God grants in the Supper is veracious, the internal substance of the sacrament is joined with the visible signs; and as the bread is distributed by hand, so the body of Christ is communicated to us, so that we are made partakers of it
– John Calvin, Short Treatise on the Lord’s Supper
the bread and the wine are visible signs, which represent to us the body and the blood; but that the name and title of body and blood is attributed to them, because they are as instruments by which our Lord Jesus Christ distributes them to us.
– John Calvin, Short Treatise on the Lord’s Supper