In this Sacrament we have such full witness of all these things that we must certainly consider them as if Christ here present were himself set before our eyes and touched by our hands. For his word cannot lie or deceive us: “Take, eat, drink: this is my body, which is given for you; this is my blood, which is shed for forgiveness of sins” [Matthew 26:26-28, conflated with 1 Corinthians 11:24; cf. Mark 14:22-24; Luke 22:19-20]. By bidding us take, he indicates that it is ours; by bidding us eat, that it is made one substance with us; by declaring that his body is given for us and his blood shed for us, he teaches that both are not so much his as ours. For he took up and laid down both, not for his own advantage but for our salvation. And, indeed, we must carefully observe that the very powerful and almost entire force of the Sacrament lies in these words: “which is given for you,” “which is shed for you.” The present distribution of the body and blood of the Lord would not greatly benefit us unless they had once for all been given for our redemption and salvation. They are therefore represented under bread and wine so that we may learn not only that they are ours but that they have been destined as food for our spiritual life. And so as we previously stated, from the physical things set forth in the Sacrament we are led by a sort of analogy to spiritual things. Thus, when bread is given as a symbol of Christ’s body, we must at once grasp this comparison: as bread nourishes, sustains, and keeps the life of our body, so Christ’s body is the only food to invigorate and enliven our soul. When we see wine set forth as a symbol of blood, we must reflect on the benefits which wine imparts to the body, and so realize that the same are spiritually imparted to us by Christ’s blood. These benefits are to nourish, refresh, strengthen, and gladden. For if we sufficiently consider what value we have received from the giving of that most holy body and the shedding of that blood, we shall clearly perceive that those qualities of bread and wine are, according to such an analogy, excellently adapted to express those things when they are communicated to us.

—John Calvin, Institutes of the Christian Religion, (IV, xvii, 3), translated by Ford Lewis Battles.