The Greek word used for “fellowship” in this passage is “koinonia.”
Koinonia, as noted above, has pagan religious overtones. It also is used to describe the business relationship of small partnership companies, like Peter’s fishing business.
But the primary Christian meaning is “Communion.” It shows up again in 1 Corinthians 10:16, for example:
“The chalice [poterion] of blessing that we bless, is it not a communion [koinonia] in the blood of Christ? The bread which we break, is it not a communion [koinonia] in the body of Christ?”
“Metoche”, the word used for “partnership” in the passage, means “someone who shares with you, or who partakes along with you.” It’s another word commonly used in passages about Communion.
Usually, there’s not much difference between traditional Catholic or Orthodox versions of the Bible, and Protestant or modernist versions of the Bible. But when there is a difference, it’s a doozy… and this passage is an example.
Paul is saying that pagans and unbelievers have no business receiving Communion in the Church, until and unless they do believe. Why would you want people who currently participate in pagan sacrifices to the gods, and who eat sacrificial meat in order to commune with their gods, also receiving Jesus’ Body and Blood? Wouldn’t that be saying that Jesus is just the same as the false gods, no better and no worse?
- “poterion” is the Septuagint translation for Hebrew “kos”. It means a goblet for wine, in most circumstances, but it seems to have been connected with stuff that went on in the Temple. It showed up on Jewish coinage and on the Roman triumphal monument commemmorating the destruction of the Temple and the capture of the sacred vessels. So there’s a reason why older translations often used the more formal “calix,” chalice, and not one of the less formal words for wine drinking vessels.