You Cannot Drink Both Cups

Idol worship sounds like someone else’s sin. Ours is quieter. We keep one foot at the Lord’s table and one foot somewhere else, and we tell ourselves the second place doesn’t count because our heart isn’t really in it. Paul heard that excuse in Corinth, and his answer is the First Reading: you cannot drink the cup of the Lord and the cup of demons. Jesus heard the same excuse in Galilee, dressed up in pious words, and his answer is the Gospel: why do you call me “Lord, Lord,” and not do what I tell you? Both readings are about the gap between what we say at the altar and what we do when the stream rises. Both insist the gap is a foundation problem, and foundations are settled long before the flood arrives. Today the Church also keeps the optional memorial of the Most Holy Name of Mary, the one disciple whose “Lord” and whose life never came apart. So today’s question is simple: which cup are you actually drinking from, and what is your house standing on?

The Readings

First Reading: 1 Corinthians 10:14-22

Therefore, my beloved, shun the worship of idols. I speak as to sensible men; judge for yourselves what I say. The cup of blessing which we bless, is it not a participation in the blood of Christ? The bread which we break, is it not a participation in the body of Christ? Because there is one bread, we who are many are one body, for we all partake of the one bread. Consider the practice of Israel; are not those who eat the sacrifices partners in the altar? What do I imply then? That food offered to idols is anything, or that an idol is anything? No, I imply that what pagans sacrifice they offer to demons and not to God. I do not want you to be partners with demons. You cannot drink the cup of the Lord and the cup of demons. You cannot partake of the table of the Lord and the table of demons. Shall we provoke the Lord to jealousy? Are we stronger than he?

Gospel: Luke 6:43-49

“For no good tree bears bad fruit, nor again does a bad tree bear good fruit; for each tree is known by its own fruit. For figs are not gathered from thorns, nor are grapes picked from a bramble bush. The good man out of the good treasure of his heart produces good, and the evil man out of his evil treasure produces evil; for out of the abundance of the heart his mouth speaks.

“Why do you call me ‘Lord, Lord,’ and not do what I tell you? Every one who comes to me and hears my words and does them, I will show you what he is like: he is like a man building a house, who dug deep, and laid the foundation upon rock; and when a flood arose, the stream broke against that house, and could not shake it, because it had been well built. But he who hears and does not do them is like a man who built a house on the ground without a foundation; against which the stream broke, and immediately it fell, and the ruin of that house was great.”

Scriptural Analysis

Paul has been circling this subject for three chapters. Chapter 8 handled meat that had once been offered to an idol, and he was fairly relaxed about it, so long as nobody’s weak conscience got trampled. Chapter 9 offered his own example of giving up rights for others. The first half of chapter 10 held up Israel in the wilderness, baptized in the sea, fed with spiritual food, and still struck down for idolatry. Now he arrives at the center of the argument, and the center is the Eucharist. “Therefore” tells you he is drawing the conclusion. “Shun the worship of idols” is literally “flee from idolatry,” and the added “from” makes it even more emphatic than his earlier “flee fornication” (1 Corinthians 6:18). Prudence toward a weaker brother was chapter 8. Sitting down at a pagan sacrificial banquet is sacrilege.^[1]

Two small words tell you how much Paul cares. The “therefore” (Greek dioper) shows up only twice in all his letters, both times in this section (1 Corinthians 8:13; 10:14). And “beloved” replaces his usual “brothers”; he uses it of the Corinthians only here and at 15:58. He is about to say something hard, and he wants them to know it comes from affection.^[2] He also refuses to demand blind obedience: “judge for yourselves what I say.” He gives this reason: what they do every Sunday.

“The cup of blessing which we bless.” The phrase comes from the Jewish table, the third ceremonial cup of the Passover meal, over which the father of the family gave thanks. Paul lifts it and sets it beside the pagan libation to say: we have a sacrifice too. Notice the order: cup before bread. It reverses the institution narrative of chapter 11 but matches the Didache, a Christian document from the end of the first century, which shows how early this eucharistic language was fixed. The key word is koinonia, “participation.” It means a real sharing in a thing, an intimate union with a person, and the community that union creates, and all three are in play. To drink the cup is to share in the blood of Christ, to be joined to Christ, and to be made one with everyone else who drinks it.^[3]

Then Paul says something the Church has never stopped repeating: “Because there is one bread, we who are many are one body, for we all partake of the one bread.” For Paul, that unity is as real as the body of Christ, because that is what the Eucharist is. Baptism joins us to the body once; the Eucharist keeps doing it, meal after meal. We become what we consume. The Catechism cites this exact verse when it teaches that the Eucharist makes the Church, and Saint Thomas Aquinas says the reality the sacrament finally produces, its res, is the unity of the Mystical Body.^[4] Saint John Chrysostom, preaching on this passage, put the contrast between the two altars in a single line. Paul is telling them, he says, if you want blood, do not redden the altar of idols with the slaughter of beasts, but my altar with my blood.^[5]

Verses 18 through 21 make the argument airtight. Israel’s priests who ate the sacrifices were “partners in the altar,” and the altar stood for the Lord himself. Eating the sacrificial meal was union with the one who received it. So what about the pagan meals? Paul grants that the idol is nothing and the meat is nothing. The act is another matter. Quoting Deuteronomy 32:17, he says that what pagans sacrifice, they offer to demons. To sit at that table, even as an “enlightened” Christian who knows the god is a fiction, is to become a partner with demons, because the act expresses a belief the person claims not to hold, and it opens a door. “Table” in verse 21 is simply another word for “altar,” as it is in Malachi 1:7 and 12, which is why the Council of Trent read this verse as Paul comparing two sacrifices, and why the Mass is one.^[6]

The last two questions are the sharpest. “Shall we provoke the Lord to jealousy?” God’s jealousy in the Old Testament is the jealousy of a husband, because he bound himself to his people by a marriage covenant (Deuteronomy 6:14-15; Hosea 2). Drinking from both cups is adultery. “Are we stronger than he?” The Targum on Deuteronomy 32 actually pictures idolatry as a contest of strength with the Lord. Paul lets the absurdity sit there, and he says “we,” including himself in the warning.^[7]

Now the Gospel, which closes the Sermon on the Plain. Jesus has just finished with the blind guide and the beam in the eye, and he moves without a break to trees and fruit. The connection is tight: a person cannot bring anyone else to good by criticism alone. His own deeds must come first and show who he is. The image of two ways is old. Deuteronomy 30:15-20 set life and death before Israel; Psalm 1 pictured the righteous man as a tree planted by streams of water; and the early Church used the “two ways” as its standard way of teaching converts. The ancient world took it as plain fact that character precedes action: what a man does reveals what his heart already is. That is why hypocrisy stings. It is the attempt to fake the fruit.^[8] Bede reads the whole section as still aimed at the hypocrite: what you put forward in words, make up also in works. And Chrysostom warns that when you hear a man say abominable things, do not imagine the evil in him is only as large as his words. The fountain is more copious than the stream.^[9]

Then the turn. “Why do you call me ‘Lord, Lord,’ and not do what I tell you?” Two things are happening here. First, the sheer authority of it. Where the Old Testament said, do what God commands, Jesus says, do what I command. Only the God who revealed himself to Moses on Sinai can talk that way (Exodus 34:6), and Luke wants you to feel that the sermon has been about a person all along, a divine teacher whose disciples become like him (Luke 6:40). Second, the target. Up to this point in Luke, only Peter and the leper have called Jesus “Lord” (Luke 5:8, 12), so the rebuke is aimed past them, at Christians who profess the faith and do not live it. Luke is writing to us.^[10]

The parable of the two builders answers Paul’s two cups with two houses. Bede says the rock is Christ, and that “dug deep” means the man let the precepts of humility dig out all earthly motives from his heart, so he would not serve God for temporal gain. Basil says to lay your foundation on the rock is to lean on the faith of Christ and stay unmoved in adversity, whether it comes from man or from God. Ambrose says obedience to the commandments is the foundation of every virtue, the thing that keeps the house from being moved by the torrent of pleasures or the storms of this world. And Chrysostom draws the blunt lesson: faith profits a man nothing if his manner of life is corrupt.^[11]

One detail from the ground. Elaborate foundations were unusual in Palestinian houses, which is exactly why Luke’s builder is remarkable. He dug deep on purpose, before there was any water in the wadi. Luke’s flood is a single river bursting its banks, the kind of torrent that comes down a dry desert channel in the rainy season and clears everything that is unanchored. The two houses look identical on a sunny day. The difference shows only when the flood comes, and Luke means that flood on two levels: the opposition Jesus already promised his disciples (Luke 6:22), and the judgment at the end. “The ruin of that house was great” is a verdict.^[12]

Pope Benedict XVI, commenting on this passage, said that those who build their lives on Christ’s word build in a sound and lasting way, while possessions, pleasure, and power show themselves sooner or later to be incapable of satisfying the deepest longings of the human heart.^[13] That is where Paul and Luke meet. A person cannot drink from two cups, because he can only have one foundation. Whatever you actually partake of, whatever you actually do when the pressure is on, that is your rock, and everything else is just what you call it.

Daily Application

Paul’s Corinthians went to the Lord’s Supper. They also went to the temple banquets, because their patrons expected it, their business ran through it, and declining invitations week after week would cost them friends. They told themselves the idol was nothing, which was true, and that therefore the meal was nothing, which was false. The modern commentary on this passage names the trap exactly: to believe one thing and do another, for whatever reason, even just to be social, erodes whatever belief you started with. Every time you sit at the second table, the first table means a little less.^[14]

Today’s readings ask you to take an honest inventory of your tables. The office culture that requires you to laugh along. The friend group where the faith is quietly understood to be off the table. The screen you sit in front of at night that feeds you a picture of the good life the Gospel flatly contradicts. And the more literal cases Paul’s own warning covers: the tarot deck, the horoscope, and the “harmless” occult game, which are not harmless. Each of these is something, precisely because you keep going back. Paul’s word for all of it is “flee,” and he chose that verb over “manage” or “balance” on purpose.

The second thing is harder, because it turns from the tables you sit at to the words you say. Every Sunday you say “Lord” in the Creed, in the Gloria, in the moment before Communion. Jesus is asking you today whether the word has a life behind it. The test he gives is concrete: what do you do with his words after you have heard them? Do you forgive the person he told you to forgive? Do you give to the one who begs from you? Do you stop judging your brother’s speck? Those commands came just before this passage (Luke 6:27-42), and they are the foundation he means. Digging deep is the unglamorous work of obeying him in the specific things he said, before any storm makes it urgent.

Because the storm will make it urgent. That is the mercy in the parable. Jesus speaks of the flood as a certainty, “when a flood arose,” and he means it. The diagnosis, the layoff, the child who walks away from the faith, the marriage that hits rock bottom, the death you didn’t see coming. These are the torrents, and they ignore what you called yourself and test what you were standing on. The reason to dig deep now, in ordinary time, on an ordinary Saturday, is that you cannot pour a foundation while the water is rising.

Look at Mary. Today the Church honors her name. Ask why a name deserves honor, and the Gospel answers with what she told the servants at Cana: do whatever he tells you (John 2:5). Jesus himself said his mother and brothers are those who hear the word of God and do it (Luke 8:21), and when a woman in the crowd blessed the womb that bore him, he answered, blessed rather are those who hear the word of God and keep it (Luke 11:28). Both sayings are the explanation of her. Her “let it be done to me according to your word” (Luke 1:38) is the deepest foundation any human being ever dug, and the flood that broke against her at the foot of the Cross could not shake it. The name of Mary is honored because there was never any daylight between what she said and what she did.

So drink from the one cup. Actually, mean the “Lord” you say. Then pick one command of his you have been hearing without doing, and do it today, while the wadi is still dry.

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Notes

1. George T. Montague, First Corinthians, Catholic Commentary on Sacred Scripture (Grand Rapids, MI: Baker Academic, 2011), 172. ↩
2. Raymond F. Collins, First Corinthians, Sacra Pagina 7 (Collegeville, MN: Liturgical Press, 1999), 377-379. ↩
3. Montague, First Corinthians, 172-174; Collins, First Corinthians, 375-376, 379. ↩
4. Montague, First Corinthians, 174; Catechism of the Catholic Church, 2nd ed. (Vatican City: Libreria Editrice Vaticana, 1997), no. 1396; Thomas Aquinas, Summa Theologiae III, q. 73, a. 3. ↩
5. John Chrysostom, Homilies on 1 Corinthians 24.3, quoted in Montague, First Corinthians, 173. ↩
6. Montague, First Corinthians, 175-176; Collins, First Corinthians, 380-381. ↩
7. Montague, First Corinthians, 177; Collins, First Corinthians, 381-382. ↩
8. Pablo T. Gadenz, The Gospel of Luke, Catholic Commentary on Sacred Scripture (Grand Rapids, MI: Baker Academic, 2018), 136; Luke Timothy Johnson, The Gospel of Luke, Sacra Pagina 3 (Collegeville, MN: Liturgical Press, 1991), 114; Joseph A. Fitzmyer, The Gospel According to Luke I-IX, Anchor Bible 28 (Garden City, NY: Doubleday, 1981), 643. ↩
9. Bede and John Chrysostom, in Thomas Aquinas, Catena Aurea: Commentary on the Four Gospels, Collected out of the Works of the Fathers, vol. 3, St. Luke (Oxford: John Henry Parker, 1843), on Luke 6:43-45. ↩
10. Gadenz, Gospel of Luke, 136; Johnson, Gospel of Luke, 114. ↩
11. Bede, Basil, Ambrose, and John Chrysostom, in Aquinas, Catena Aurea, vol. 3, St. Luke, on Luke 6:46-49. ↩
12. Fitzmyer, Gospel According to Luke I-IX, 644; Johnson, Gospel of Luke, 116. ↩
13. Benedict XVI, Verbum Domini, no. 10, quoted in Gadenz, Gospel of Luke, 137. ↩
14. Montague, First Corinthians, 178. ↩

Books Cited

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• George T. Montague, SM, First Corinthians, Catholic Commentary on Sacred Scripture (Baker Academic, 2011)
• Raymond F. Collins, First Corinthians, Sacra Pagina 7 (Liturgical Press)
• Catholic Church, Catechism of the Catholic Church, 2nd ed. (Doubleday/Image, 2003)
• Pablo T. Gadenz, The Gospel of Luke, Catholic Commentary on Sacred Scripture (Baker Academic, 2018)
• Luke Timothy Johnson, The Gospel of Luke, Sacra Pagina 3 (Liturgical Press)
• Joseph A. Fitzmyer, SJ, The Gospel According to Luke I-IX, Anchor Bible 28 (Doubleday, 1981)
• St. Thomas Aquinas, Catena Aurea: Commentary on the Four Gospels, 4-volume set (Baronius Press)