Why Can't My Non-Catholic Guests Receive Communion at Mass?
When my non-Catholic friends attend Mass with me on Sunday, I think it is very rude not to offer them Communion. They will want to know why since they readily invite Catholics to take communion in their Church. Even though the missalette has an explanation, I would like to know why they must be excluded.
The Nicene Creed tells us that "We believe in One, Holy, Catholic and Apostolic Church." These are called the "marks" of the Church and they describe for us a way to recognize the true Church of Jesus Christ. The answer to your question starts with that first mark: The Church is ONE.
As St Paul tells the Ephesians, we are called to be "one body and one Spirit, as you were also called to the one hope of your call; one Lord, one faith, one baptism;" [Eph 4:5] and he tells the Corinthians, "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? Because the loaf of bread is one, we, though many, are one body, for we all partake of the one loaf. [1 Cor 10: 16-17] St. Paul emphasizes over and over again the connection between the "One Bread" (The Holy Eucharist) and the "One Body" (the Church). By our reception of Holy Communion, we are proclaiming our oneness of faith as we recognize that we share in the oneness of Christ's Body; real and substantially present in Holy Communion.
Because we are witnessing this oneness in Christ, to allow those who do not share that oneness of faith with us to receive the sign of our unity, we are telling Christ that we are one when, in fact, we are not. That is a lie. And, as with all occasions when we lie to God, there are serious consequences.
For as often as you eat this bread and drink the cup, you proclaim the death of the Lord until he comes. Therefore whoever eats the bread or drinks the cup of the Lord unworthily [those in a state of mortal sin] will have to answer for the body and blood of the Lord...For anyone who eats and drinks without discerning the body, [those who do not share our beliefs] eats and drinks judgment on himself. [1 Cor 11:26-27,29]
And this is not a new idea in Catholicism. St Ignatius of Antioch, in the year A.D. 110 wrote in his Epistle to the Smyrnaeans,
"Take note of those who hold heterodox opinions on the grace of Jesus Christ which has come to us and see how contrary their opinions are to the mind of God…They abstain from the Eucharist, and from prayer, because they do not confess that the Eucharist is the flesh of our Savior Jesus Christ, flesh which suffered for our sins in which the father, in his goodness, raised up again."
Here St. Ignatius is referring to those outside the oneness of our faith and how they abstain from the Eucharist.
So what can we say to those visitors at the Mass about receiving communion? Tell them, in our Church, when you receive Holy Communion, you are saying that you believe that the bread and wine is no longer bread and wine, but really and truly the Body and Blood of the Lord: "The Body of Christ." "Amen." Secondly, in the very act of receiving Holy Communion they are proclaiming to God the unity of their beliefs with those of the Catholic Church. In both cases, they would be lying to God.
We should never encourage our friends to lie to God! Instead, encourage them to pray that some day, our oneness of faith will be restored and, on that day, when the Eucharistic Minister says, "The Body of Christ." they can truthfully say, "Amen."