The two halves of this verse are similar in construction, though the first half is made more complicated by the clause which we bless. The difficulties of translating this verse are shown by the fact that both Revised Standard Version and Good News Bible use many more words than are in the Greek.

These two sentences are rhetorical questions. Translators in many languages will need to translate them as statements, as Good News Bible has done.

In 16a The cup (with the article The) suggests, as in verse 1, that Paul’s reader already knows which cup he is referring to. The reference is to a common practice in the church. The situation is, however, complicated by the fact that in Jewish meals, especially the Passover, the phrase “cup of blessing” was also used.

The we is not emphasized. It almost certainly refers to Christians in general, but without implying any contrast between Christians and Jews (compare verse 18).

In a Jewish setting the phrase The cup of blessing would mean “the cup over which a prayer of blessing is spoken,” and to bless a material object would mean “to give thanks to God for it.” So translators would be wise to adopt a translation similar to that of Good News Bible, “the cup we use in the Lord’s Supper and for which we give thanks to God” or “the cup we use in the Lord’s Supper, over which we say a prayer of thanksgiving to God.”

The difference between participation (also New International Version) and “communion” (Revised Standard Version footnote) is that participation means “sharing” with one another, while “communion” focuses on the relation between the believer and Christ, which is certainly also involved. (New Jerusalem Bible, New Revised Standard Version have “sharing”; Revised English Bible “means of sharing.”) The following verses suggest that Paul is thinking mainly about the union of Christians with one another. However, the idea of participation is also required by the reference to Christ’s blood and body. Perhaps one could combine these ideas as Barrett does: “a common participation in the body of Christ”; Die Bibel im heutigen Deutsch translates more fully: “Think of the communion cup over which we speak the prayer of thanksgiving. Does it not enable us to share in the blood that Christ poured out for us?”

Blood here should be translated literally, since the comparison is between two liquids. Similarly, in 16b it is probably best to keep the literal translation of body.

An alternative translation model for this verse is:
• When we drink (wine) from the cup that we use in the Lord’s supper, for which we give thanks to God, we are really sharing in the blood of Christ. And when we break the bread and eat it, we are really sharing in the body of Christ.

Quoted with permission from Ellingworth, Paul and Hatton, Howard A. A Handbook on Paul’s First Letter to the Corinthians, 2nd edition. (UBS Handbook Series). New York: UBS, 1985/1994. For this and other handbooks for translators see here .