In a thread at TitusOneNine, commenter Ross makes a marvelous theological argument for letting the unbaptized take communion.
He starts by agreeing that, to the extent that the Eucharist is a sacrifice, it would seem to some that the sacrament "should be open only to those who are bound in the New Covenant, i.e., the baptized."
But, he continues, under an even older tradition of hospitality, going back at least to Genesis 18:
... it is an ironclad rule that the stranger must be welcomed and offered the best of what you have… and if the Body and Blood of Christ is not the best we have, what is?
So I see these two strands producing conflicting answers as to whether the table should be open to the unbaptized; on the one hand it seems forbidden, on the other it seems mandatory.
Faced with this dilemma, I fall back on God’s grace. I feel we should open the table to any who come — at least, any who come in good will and humility — and let the Body of Blood of Christ work upon them whatever it will work, trusting God that it will be to their good.
“Be not forgetful to entertain strangers: for thereby some have entertained angels unawares.” (Heb 13:2)
(Bold-face emphasis added.)
In a later comment, Ross reconsiders whether, even under the sacramental view of the Eucharist, communion should be withheld from the unbaptized. He approaches the question by methodically examining the possibilities whether communion is the same for the baptized as for the unbaptized, and concludes:
The Body and Blood work some good upon the unbaptized, even though it is not the same as the good worked upon the baptized. What that good might be we can speculate; it might, for instance, be a means of drawing someone into the Church. John Wesley believed that the Eucharist could be used in this way. This is where I plant my flag; mostly because I don’t see how the Body and Blood of Christ can not be good for anyone. And, of course, if this is true then we should invite the unbaptized to the table to receive whatever good thing they can receive from it.
(Emphasis in original.)
In another comment on the same thread, I reprised my reexamination last year of 1 Cor. 11, often claimed as justification for excluding the unbaptized from the Eucharist. Read in context, when Paul criticized the Corinthians for their unworthy receipt of the body and blood, he was concerned, not for the purity of the communion ritual, but for the less-regarded members of the Body of Christ.