Calvin's doctrine of the Lord's Supper

This is from http://archbishopcranmer.com/maundy-thursday-church-divided-united-eucharistic-mystery/

For Calvin, the institution of the Supper was Christ’s ‘seal’ of his sermon in John 6, and he termed it a ‘mystical union’. Calvin believed that there is a real ‘spiritual’ reception of the body and blood of Christ in the Supper. The sacrament is a real means of grace – a channel by which Christ communicates himself. Luther and Calvin agreed that communion with a present Christ who actually feeds believers with his body and blood is what makes the sacrament. The question between them was the manner in which Christ’s body exists and is given to believers. Calvin held that, while Christ is bodily in heaven, distance is overcome by the Holy Spirit, who vivifies believers with Christ’s flesh. Thus the Supper is a true communion with Christ, who feeds believers with his body and blood. Calvin’s view of the Lord’s Supper appears to be a median position between the views of Luther and Zwingli, but it is in fact an independent position. Rejecting both Zwingli’s ‘memorialism’ and Luther’s ‘monstrous notion of ubiquity’, he held that there is a real reception of the body and blood of Christ in the Supper, but in a spiritual manner. With Zwingli, Calvin held that after the ascension Christ retained a real body which is located in heaven:

Nothing should be taken from Christ’s ‘heavenly glory’, as happens when he is brought under the corruptible elements of this world, or bound to any earthly creatures… Nothing inappropriate to human nature (should) be ascribed to his body, as happens when it is said either to be infinite or to be put in a number of places at once.

Calvin rejected the doctrine of the absorption of Christ’s humanity by his divinity, and any weakening of the idea of a local presence of the flesh of Christ in heaven. The Supper is a true communion with Christ, who feeds believers with his body and blood.

…in the sacred Supper, we acknowledge a miracle which surpasses both the limits of nature and the measure of our sense… But we must have done with all inventions inconsistent with the explanation lately given, such as the ubiquity of the body, the secret inclosing under the symbol of bread, and the substantial presence on earth.

Calvin held that the essence of Christ’s body was its power. In itself it is of little value since it ‘had its origin from earth, and underwent death’, but the Holy Spirit, who gave Christ a body, communicates his power to believers so that they receive the whole Christ in communion. The difference from Luther here is not great, for he held that the ‘right hand of God’ to which Christ ascended meant God’s power, and that power is everywhere. The real difference lay in the present existence of Christ’s body. Both agreed that there is deep mystery which can be accepted though not understood:

If anyone should ask me how this (partaking of the whole Christ) takes place, I shall not be ashamed to confess that it is a secret too lofty for either my mind to comprehend or my words to declare… I rather experience than understand it.