Open communion is the practice in some Christian churches in which anyone who presents himself for Holy Communion will be served. Churches practicing open communion do not restrict communion based on denominational affiliation or belief in Christ but rather leave the decision to receive communion to the individual.
Arguments for and against
Opponents of open communion cite the Apostle Paul's statement (I Corinthians 11:29) that "he that eateth and drinketh unworthily, eateth and drinketh damnation to himself" to say that unbelievers should not partake in the Lord's Supper. In addition, they say, Jesus was careful to not initiate the Lord's Supper until Judas the unbeliever had left.