13.For we are all baptized by one Spirit. Here there is a proof brought forward from the effect of baptism. “We are,” says he, “engrafted by baptism into Christ’s body, so that we are by a mutual link bound together as members, and live one and the same life. Hence every one, that would remain in the Church of Christ, must necessarily cultivate this fellowship.” He speaks, however, of the baptism of believers, which is efficacious through the grace of the Spirit, for, in the case of many, baptism is merely in the letter — the symbol without the reality; but believers, along with the sacrament, receive the reality. Hence, with respect to God, this invariably holds good — that baptism is an engrafting into the body of Christ, for God in that ordinance does not represent anything but what he is prepared to accomplish, provided we are on our part capable of it. The Apostle, also, observes here a most admirable medium, in teaching that the nature of baptism is — to connect us with Christ’s body. Lest any one, however, should imagine, that this is effected by the outward symbol, he adds that it is the work of the Holy Spirit.
Whether Jews or Greeks. He specifies these instances, to intimate, that no diversity of condition obstructs that holy unity which he recommends. This clause, too, is added suitably and appropriately, for envy might at that time arise from two sources — because the Jews were not willing that the Gentiles should be put upon a level with them; and, where one had some excellence above others, with the view of maintaining his superiority, lie withdrew himself to a distance from his brethren.
We have all drunk in one Spirit. It is literally, “We have drunk into one Spirit,” but it would seem that, in order that the two words ἐν (in) and ἑν (one) might not immediately follow each other, Paul intentionally changed ἐν (in) into ἐις (into,) as he is accustomed frequently to do. Hence his meaning seems rather to be, that we are made to drink through the influence, as he had said before, of the Spirit of Christ, than that we have drunk into the same Spirit. It is uncertain, however, whether he speaks here of Baptism or of the Supper. I am rather inclined, however, to understand him as referring to the Supper, as he makes mention of drinking, for I have no doubt that he intended to make an allusion to the similitude of the sign. There is, however, no correspondence between drinking and baptism. Now, though the cup forms but the half of the Supper, there is no difficulty arising from that, for it is a common thing in Scripture to speak of the sacraments by synecdoche. (752) Thus he mentioned above in the tenth chapter (1 Corinthians 10:17) simply the bread, making no mention of the cup. The meaning, therefore, will be this — that participation in the cup has an eye to this — that we drink, all of us, of the same cup. For in that ordinance we drink of the life-giving blood of Christ, that we may have life in common with him — which we truly have, when he lives in us by his Spirit. He teaches, therefore, that believers, so soon as they are initiated by the baptism of Christ, are already imbued with a desire of cultivating mutual unity, (753) and then afterwards, when they receive the sacred Supper, they are again conducted by degrees to the same unity, as they are all refreshed at the same time with the same drink.