1 Corinthians 10:15

I speak as to wise men; judge ye what I say (KJV)

Then: "You're smart! Figure this out yourself." Since all learning comes through interaction with material being presented, Paul tells the Corinthians to use their own powers of judgement and discernment. They need to think about what he's just said and about what's coming next. The Gentiles ate and drank during temple celebrations where they remembered their idols. Christians ate and drank during celebrations remembering Christ and his words at the last supper. If they will, the Corinthians can use their wisdom and see what they're doing wrong.

Now: What Paul says becomes so embedded in our early introduction to Christ that his comments do not seem like new revelations. We've already accepted them and base spiritual growth upon them. To go back and rethink is useful for clarity when making new decisions, but it's just peripherally interesting to note the relation of communion to eating meat offered to idols.