14 Therefore, my beloved, flee from idolatry. 15 I speak as to sensible people; judge for yourselves what I say. 16 The cup of blessing that we bless, is it not a participation in the blood of Christ? The bread that we break, is it not a participation in the body of Christ? 17 Because there is one bread, we who are many are one body, for we all partake of the one bread. 18 Consider the people of Israel: are not those who eat the sacrifices participants in the altar? 19 What do I imply then? That food offered to idols is anything, or that an idol is anything? 20 No, I imply that what pagans sacrifice they offer to demons and not to God. I do not want you to be participants with demons. 21 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. 22 Shall we provoke the Lord to jealousy? Are we stronger than he? 1 Corinthians 10:14–22 (ESV)

4 principles about the illustration of the Lord’s Supper that help the Corinthians to flee from idolatry.

Participating in the eating of the bread and the drinking of the cup is a type of fellowship with Christ. (v. 16)

Participating in the eating of the bread and the drinking of the cup in the Lord’s supper generates a type of fellowship/partnership/communion with fellow believers.  

13 For in one Spirit we were all baptized into one body—Jews or Greeks, slaves or free—and all were made to drink of one Spirit. 1 Corinthians 12:13 (ESV)

The emphasis on Christ’s blood infers the gravity of our covenant relationship to Christ.
25 In the same way also he took the cup, after supper, saying, “This cup is the new covenant in my blood. Do this, as often as you drink it, in remembrance of me.” 1 Corinthians 11:25 (ESV)

Fellowship with Christ and fellowship with the entities of the world do not mix.
14 Do not enter the path of the wicked, and do not walk in the way of the evil. Proverbs 4:14 (ESV)

We should be careful about individuals with whom we associate and how this could affect our mindset and our reputation as children of God.

 We should be very careful about groups and associations with which we fellowship as a church, asking, do they represent the same gospel as we do.