Matthew 9:11, The Closed Communion
When the Pharisees saw this, they asked his disciples, “Why does your teacher eat with tax collectors and sinners?”
//It would seem that one of the hardest examples for Jesus’ followers to accept was his willingness to eat with anyone. That just simply wasn’t done; you don’t share your table with others below your caste. Not as a Jew in Jesus’ day.
But Paul understood. It disturbed Paul greatly when his fellow Christians struggled with this precept. He soundly criticized Peter for his failure in this matter:
For before that certain came from James, [Peter] did eat with the Gentiles: but when they were come, he withdrew and separated himself, fearing them which were of the circumcision. –Galatians 2:12
In this example, those who were “of the circumcision” are Jewish Christians, who would not eat with Gentile Christians. So, already, denominational boundaries were being drawn.
The first century Christian document The Didache takes the separation of members from nonmembers for granted, indicating that only baptised members may eat together at the same table. Curiously, many denominations still struggle with this issue. The Eucharist grew out of the tradition of sharing bread and wine together at the table (it was originally shared as a whole meal, not a nibble of bread and sip of wine), and many churches, including Protestants, accept only members of their own church at the communion table.