The sacraments in 1 Corinthians 10

Baptism 

“For I do not want you to be ignorant of the fact, brothers and sisters, that our ancestors were all under the cloud and that they all passed through the sea.”- v.1

Paul introduces the adminitions to the Corinthians by a reference to their spiritual ancestors- the Hebrew people, the generation of Moses, who were baptized into Moses in the cloud and in the sea (v.2). Nevertheless, God through the cloud and the sea delivered them from destruction and brought them salvation in two ways: through the cloud- God Himself walked in front of them manifesting by means of a pillar of fire at night and a cloud by day- guiding their path, moving them toward the promised land, redeeming them from the land of bondage and delivering them over to a state of life. “Through the sea” God delivered them from the Egyptians, for some of them however this baptism of the sea did not move them to a renunciation of the old life, and while bodily were far from Egypt, they were with their hearts far from the Lord and in spiritual Egypt. (Acts 7:39) 

This is an image of baptism, where God guiding our path moving us toward eternal life and the heavenly kingdom, redeemes us from sin, death and the devil, and takes us out of the land of bondage and freeing us from slavery to sin. Just as passing through the Red Sea was the moment this happened for the Israelites, baptism represents God offering us redemption and renewal through water and the Spirit, by crucifying our old self with Christ and ressurecting us in Him. In this baptism He also redeemed us from our spiritual enemies, as He did the Israelites, - sin, death and the devil; or it can be said that we participated in the benefits that Christ acquired for us on calvary. By baptism the believing are saved from the slavery of sin, from the oppressor the devil, and by the efficacy of Christ’s passion communicated to us in baptism remits the guilt of all sins. However, there are some outwardly baptized who do not benefit from it, just as some bodily passed from Egypt and walked toward the promised land, yet their hearts remained in Egypt and they even desired to be back in slavery when met with difficulties. So it happens that some visibly baptized with water are not regenerated, who remain in a land of sin and desire not eternal salvation. However, to those whom the Holy Spirit prepares their hearts by prevenient grace, baptism is to them salvation to the fullest extent- a bestowal of the benefits of Christ's death and ressurection (Rom 6:3-5). 

The Lord’s Supper

“They all ate the same spiritual food and drank the same spiritual drink; for they drank from the spiritual rock that accompanied them, and that rock was Christ.”- v. 3-4

It is rightly said that in some manner, the Jews themselves fed upon Christ spiritually, to this effect our Lord says John 6 Jesus said to them, “Very truly I tell you, it is not Moses who has given you the bread from heaven, but it is my Father who gives you the true bread from heaven. For the bread of God is the bread that comes down from heaven and gives life to the world.” The spiritual eating of Christ can be understood in two senses: 1) as a metaphor for the effects of faith- namely, we experience peace of conscience, joy and a desire for righteousness, to experience the mighty work of God's grace, the remission of sins and eternal life (benefits that flow from faith, or union with Christ); 2) as a true, real eating of the actual body and blood that was crucified, yet not a grotesque, carnal chewing of flesh (we will explain more the meaning later by analogy)

The Contrast between the feasts of Idolaters and the Lord’s Supper

The Apostle is contrasting the pagan feast offerings with the Supper. Many consider that this is why he mentions the cup as prior to the bread, so that he might afterwards discourse concerning the meat. 

“Paul names the cup first, not because at the sacrificial feasts men thought less about food than about a pleasant meeting primarily for enjoying wine (they came for eating and drinking), but because he means to speak at more length about the bread, and in connection with it, especially to discuss the Israelitic partaking of the sacrifices, as it suited his theme of the meat offered to idols. For this reason he begins here by disposing briefly of the point concerning the cup. In chap. 11 he does otherwise, because not regarding the matter there from this special point of view.”- Meyer's NT Commentary

Now that we established that Paul makes a contrast between the feasts of Idolaters and the Lord’s Supper, let's proceed to more practical considerations. Firstly, the meaning of verse 16.

“The cup which we bless, is it not a communion with the blood of Christ?”- v. 16

In these words, εστι cannot mean signifies, but is for the following reasons: 

1. As a general exegetical rule, the literal sense is the most straightforward sense in a passage, and must be received in its most literal form, the burden of proof is always going to be on the ones supporting a non-literal reading. If a non-literal reading is preffered, it must be grounded in either of these two reasons: 1) in contradicts the context, going beyond the scope of the passage; 2) it contradicts other passages in Scripture (this must be carefully demonstrated). I judge in consensus with the protestant doctors that in exegesis, especially in discourses that treat fundamental christian dogmas essential to the faith, or exhortations and admonitions for holy living and sanctification, it is most proper and fitting that the simplest language be used for the sake of clarity, and little to no figures of speech should be allowed (only as much as does not obscure the meaning or no figures of speech). 

2. The passage that we are treating of is an exhortation unto holy living and an admonition to flee from the grave sin of idolatry, therefore it is very fitting that Paul would use clear and straightforward language to communicate such truths to the Corinthians. Therefore, according to what has been said above, verse 16 ought to be taken in a literal sense, a real communion of His body and blood inasmuch as this is both an encouragement to partake, and a warning to flee from the altar of demons.

3. If Paul means that the breaking and blessing of bread and wine only represent a participation in the body and blood of Christ (are mere symbols with no true communion), but are not by themselves a participation in the thing signified, then the admonition against idolatry would make no sense. 

If the breaking of bread and wine only represent κοινωνία (participation/communion), it means that it is not through the very act of eating faithfully that real participation is effected. However, it was through the very eating of meat sacrificed to idols (consciously) that one would have been an idolater, having real communion with demons (for only this can be the cause of idolatry), eating at the table of demons. Notice how the text does not speak of “eating demons” which would favor a figurative reading, but simply “eating things sacrificed to demons”, yet it does plainly affirm that we “eat the flesh and drink the blood of Christ”. The body and blood of Christ are not contrasted to demons, but to the things sacrificed to demons.

4. From this antithesis, we reason that the participation spoken of in this passage is actual and real, not symbolical. Thus the interpretation that in the Lord’s Supper, the bread and wine are merely outward symbols of a communion that happens inwardly outside of the act of eating, and entirely without it, is entirely ruled out by Paul in this passage. There is a difference between the sentence “This bread is my body”, and “This bread is a participation in my body”- in the former, the subject is identified with the body itself; in the latter, the subject is identified with a participation in the body- therefore the verses should not be read in the same sense. 

It is textually inappropriate to understand the words “communion of the body” as “communion of the church” as Zwingli asserted in the Colloquy of Marburg- for the church is one mystical body, only because they partake of the same food- Christ's body. By eating of the flesh of Christ, they become one mystical body. The church would not be called the body of Christ in a fitting sense if there was no communion that distributed to us His true body, thus He indwells us spiritually in a more profound sense. What can be adduced as a further argument is that since the cup is contradistinguished from the bread, and the blood from the body, respectively, the most natural interpretation is to take “body” to refer to Christ's natural body shed on the cross for our sins, and to His natural blood which satisfied the Father's wrath. Such cannot refer to the church, which is never called “the blood of Christ”, the words “body and blood” must be taken in the proper sense, otherwise the analogy of the pagan feasts is again destroyed. 

Another argument in favor of this reading is the analogy of the pagan feast. The pagans used to sacrifice meat to idols, and then after the sacrifice commenced, eat the meat that has remained- the sacrificial meat. Therefore, for Christians, the breaking of bread and the blessing of wine are a participation in the body and blood of Christ, that is, they share in the very things sacrificed for our salvation. The Jews are said to have participated in the altar ( [synecc. “Do not those who eat the sacrifices participate in the altar?” or “Do not those who eat the sacrifices partake of the things sacrificed on the altar?”], real participation is meant, the very thing sacrificed was consumed by the faithful. 

Objection. It seems that by “body” and “blood” a synecdoche would be meant, the terms being taken for what was wrought and acquired for us through the body and blood- namely, the remission of sins and eternal life, the benefits of the atonement but not the things sacrificed themselves. Therefore, we receive Christ spiritually and with all the benefits of His redemption, but not His real body and blood. 

On the Contrary, the Jews did not partake only of the effects of the altar and only of the blessings which proceeded from eating of the sacrifice (remission of sins and eternal life), but they ate the very thing sacrificed and as a consequence, shared in all benefits. Likewise, God's jealousy is said to be consequent to the eating of meat sacrificed to idols, thus distinguishing between the cause and the effect. Participating in the table of demons meant eating the meat sacrificed to idols, and God's jealousy/condemnation was a consequence of the act of eating things sacrificed to idols. In like manner, the remission of sins/justification and eternal life [the benefits of Christ’s sacrifice] are the consequence of worthily partaking of the body and blood of Christ, these two are not the same; but the former is a consequence of the latter. Therefore, there cannot be a figure of speech in the words “body” and “blood”. Therefore sharing in the benefits of Christ is a consequence of feeding spiritually upon Him. The exact mode of eating we ought not to explain more than revelation provides, what we can only say is that it is not a bodily, carnal chewing of raw flesh and raw blood and this is deduced from John 6, where Christ teaches that we ought to feast upon Him in a spiritual manner, this is also the teaching of the ancient church. Any speculation concerning Christ being in the elements physically, with or without extension and quantity, whether the elements change substance is beyond the scope of divine revelation in this passage and the secret things of God ought not to be inquired beyond what is revealed in Scripture. 

A few notes concerning spiritual eating

It must also be noted, that spiritual eating can be taken in the two senses mentioned above: 1) we receive the benefits of Christ's sacrifice, where spiritual eating is a metaphor for receiving remission of sins and eternal life; 2) an actual, spiritual yet true participation in the things sacrificed- Christ's body and blood (This mystery ought to be apprehended and piously believed by faith alone). The former spiritual eating happens in prayer, studying and meditation of God's word, hearing the spoken gospel at church, in baptism and in communion, yet as Augustine says this spiritual eating we have everytime when we are in fellowship with the spirit. The latter sense which is more profound happens in communion only, since Scripture never speaks in such clear terms and analogies communion in contrast to pagan and Jewish sacrifices except of the service of the Lord’s Supper. 

I shall end with a quote from Martin Luther concerning the beauty of God's grace given to us in Holy Communion and the efficacy of this sacrament: 

“For this reason we go to the Sacrament because there we receive such a treasure by and in which we obtain forgiveness of sins. Why so? Because the words stand here and give us this; for on this account He bids me eat and drink, that it may be my own and may benefit me, as a sure pledge and token, yea, the very same treasure that is appointed for me against my sins, death, and every calamity. On this account it is indeed called a food of souls, which nourishes and strengthens the new man. For by Baptism we are first born anew; but (as we said before) there still remains, besides, the old vicious nature of flesh and blood in man, and there are so many hindrances and temptations of the devil and of the world that we often become weary and faint, and sometimes also stumble. Therefore it is given for a daily pasture and sustenance, that faith may refresh and strengthen itself so as not to fall back in such a battle, but become ever stronger and stronger. For the new life must be so regulated that it continually increase and progress; but it must suffer much opposition. For the devil is such a furious enemy that when he sees that we oppose him and attack the old man, and that he cannot topple us over by force, he prowls and moves about on all sides, tries all devices, and does not desist, until he finally wearies us, so that we either renounce our faith or yield hands and feet and become listless or impatient. Now to this end the consolation is here given when the heart feels that the burden is becoming too heavy, that it may here obtain new power and refreshment.”- Martin Luther, Large Catechism