John 6:56

He that eateth my flesh and drinketh my blood abideth in me, and I in him.

Abideth in me ... brings into view the spiritual body of the Lord, which is his church, and the eating and drinking of his flesh and blood is a reference to serving Christ within that body, including the faithful observance of his commands relative to the Lord's Supper.

In me ... The implications of this tiny prepositional phrase are perhaps the profoundest in the entire Bible. In Paul's writings, this phrase, or its equivalent (in Christ, in him, in whom, etc.), is used 169 times. This is the Holy Spirit's manner of declaring that the concept of being "in Christ" is about the most important thing in divine revelation. See my Commentary on Romans, p. 112.

He that eateth and drinketh, etc. ... abideth in me ... The person who is faithfully observing the Lord's command regarding the Lord's Supper is abiding in Christ; and those who remove themselves from such faithful observance also remove themselves from being "in Christ." Some religionists may not find this truth to their liking; but there does not seem to be any honest way to remove such a conclusion from this text. "He that eateth and drinketh ... abideth in" Christ. Although certainly included, the Lord's Supper is not the only eating and drinking characteristic of the Christian's life. Paul declared that "In one Spirit were we all baptized into one body, whether Jews or Greeks, whether bond or free; and were all made to drink of one Spirit" (1 Corinthians 12:13). Here the receiving of the Holy Spirit is the same as to "drink of" the Holy Spirit.

And I in him ... In this passage, the mutual union of Christ and believers is spoken of as the saved being in the Lord, and as the Lord being in the saved. These are not descriptive of two states but of one. Other New Testament designations of the same condition are: "In the Spirit" (Revelation 1:10); "Spirit in you" (1 Corinthians 6:19), "he ... in God" (3:21), "God in you" (Philippians 2:12), "mind of Christ ... in you" (Philippians 2:5), "word of Christ ... in you" (Colossians 3:16). Thus the blessed union between the saved and God is variously described in the New Testament as: God in men, men in God, Christ in men, men in Christ, the Holy Spirit in men, men in the Holy Spirit, the mind of Christ in men, and the word of Christ in men. These are not eight states or conditions of spiritual life, but one, the saved state.

In fairness to the people who have so strongly resisted any idea of the Lord's Supper being referred to in this passage, it should be said that their principal concern was to guard against the gross literalization of the passage as was done in the Council of Trent and their dogmatic promulgation of the doctrine of transubstantiation, the doctrine which affirms that the bread and wine of the supper are actually changed by the blessing of the priest into the literal flesh and blood of the Son of God. However, that erroneous teaching must be guarded against in some other manner than that of stripping the reference to the holy communion out of this passage.