what about this?
http://www.faithabq.org/sacraments-baptism-holy-communion
I’m not defying -— just asking. I’m interested.
Usually the kind of experimentum crucis (if that’s the phrase I want) is that most non-Catholic, non-Orthodox groups would not say that there is a kind of identity between the Sacrament and the sacrifice of Christ. That’s an important (and misunderstood) aspect of Catholic teaching.
A quick, overly simplified overview of the 4 views of what happens at Communion/the Lord’s Supper.
Catholic - Transubstantiation - the bread and wine really and substantially become the flesh and blood of Christ. Communion is a Sacrament.
Lutheran - Consubstantiation - the body and blood of Christ is physically present in, among and alongside the bread and wine. Communion is a sacrament.
Calvinist - Christ is Spiritually, but not physically present when the elements are consumed. The Lord’s Supper is a Sacrament.
Baptist - The Lord’s Supper is a memorial. The bread and (usually) grape juice is consumed in rememberance of Christ’s sacrifice. The Lord’s Supper is an ordinance, not a sacrament.
As a side note, due to their understandings of what has happened, the Catholics and Lutherans have specific (but different) ways to handle any of the elements which might be left over. A Calvinist or Baptist can dispose of leftovers as convenient.
If a Presbyterian or a Baptist attends a Mass, the appropriate thing to do is to stand aside at the end of the pew to allow the others to pass, and then return to your seat. (I do the same at a Lutheran service). A Catholic should do the same in a Protestant church (or if the elements are served to a seated congregation, just pass the tray down the row without taking the elements).