1 Corinthians 10:15 – -17
New International Version (NIV)
15 I speak to sensible people; judge for yourselves what I say. 16 Is not the cup of thanksgiving for which we give thanks a participation in the blood of Christ? And is not the bread that we break a participation in the body of Christ? 17 Because there is one loaf, we, who are many, are one body, for we all share the one loaf.
From BibleGateway.com: http://www.biblegateway.com/passage/?search=1+corinthians+10.15-17&version=NIV