Well, katherine, since most of the protestant groups do not recognize the “Lord’s Supper” AS a sacrament, that would pretty much preclude Him being PRESENT as a sacrament.
God does not do the impossible. He cannot make a boulder so large that He could not move it, for example, because that sort of impossibility is ridiculous, and God is not ridiculous.
It is pretty clear in the Catechism what is required for a VALID sacrament. Even in our own Catholic church, if the priest were to offer up chips and soda, God would NOT be present in the chips and soda, not even if the priest really, REALLY wanted Him to be.
Valid matter, valid priesthood. Remember, God’s ways are “above our ways” doesn’t mean that, well, God is SO good that He’ll ignore any silly old RULES we have here on earth and just make everybody happy even if they aren’t conforming to His rules. That makes God into some sort of sap, IMO. It makes Him untrustworthy, and He is all trust. It makes Him arbitrary, and He is all just.
I’d be a little less inclined to the hearts-and-flowers, God only wants us all to be happy. . .and a little more inclined to the, “Be merciful to me, Lord, a sinner” outlook. God doesn’t OWE us anything. If we do His will, we’re just doing what we are SUPPOSED to do. . .why should we get any special treatment? We are his servants. Yes, we are adopted children as well, but children don’t tell their parents what to do, and children need love that is disciplined. I might my child, but if I didn’t move him away from a hot burner because I didn’t want to make him angry or upset, and he got burned, how loving am I, really?