In the Lord's Supper we are said to receive Christ and the benefits of his redemption to our spiritual nourishment and growth in grace. As our natural food imparts life and strength to our bodies, so this sacrament is one of the divinely appointed means to strengthen the principle of life in the soul of the believer, and to confirm his faith in the promises of the gospel. The Apostle teaches that by partaking of the bread and wine, the symbols of Christ's body and blood given for us, we are thereby united to him as our head, and with all our fellow believers as joint members of his mystical body. The union between the head and members of the human body and between the vine and its branches, is a continuous union. There is s constant flow of vital influence from the one to the other. In like manner the union between Christ and his people is continuous. He constantly imparts his life-giving influence to all united to Him by faith and by the indwelling of his Spirit. It has often been stated already that the Bible teaches, (1.) That Christ and his people are one; that this union is not merely a union of congeniality or feeling, but such as constitutes them one in a real but mysterious sense. (2.) That the bond of union is faith and the indwelling of the Holy Spirit, who dwelling in Him without measure is communicated from Him to all his members.
As God is everywhere present and everywhere operative by his Spirit, so Christ dwells in our hearts by faith through or in virtue of the indwelling of the Holy Ghost. (3.) He is thus our life. He works in us to will and to do according to his own good pleasure. As God works everywhere throughout nature continually controlling all natural causes each after its kind, to produce the effects intended; so does Christ work in us according to the laws of our nature in the production of everything that is good; so that it is from Him that "all holy desires, all good counsels, and all just works do proceed." It is not, therefore, we that live, but Christ that liveth in us.
As our Lord in addressing the Apostles and through them all his disciples, said this is my body and blood given for you, He says the same in the most impressive manner in this ordinance to every believing communicant: "This is my body broken for you." "This is my blood shed for you." These words when received by faith fill the heart with joy, confidence, gratitude, love, and devotion; so that such a believer rises from the Lord's table refreshed by the infusion of a new life.
The efficacy of this sacrament, according to the Reformed doctrine, is not to be referred to any virtue in the ordinance itself, whether in its elements or actions; much less to any virtue in the administrator; nor to the mere power of the truths which it signifies; nor to the inherent, divine power in the word or promise by which it is attended; nor to the real presence of the material body and blood of Christ (i. e., of the body born of the Virgin), whether by the way of transubstantiation, consubstantiation, or impanation; nor to a supernatural life-giving influence emanating from the glorified body of Christ in heaven, nor to the communication of the theanthropic nature of Christ, but only to "the blessing of Christ, and the working of his Spirit in them that receive" the sacrament of his body and blood.
--Charles Hodge, Systematic Theology, Vol. 3, p. 647.
