Here's an interesting problem for me.
Ask a non-Lutheran theologian what a Lutheran understanding of the Lord's supper is, and you will usually get the phrase that "in, with, and under" the elements, Christ's Body and Blood are offered, given, and received.
Actually, this is often the explanation given by Lutherans as well.
But it's not correct. Or it's at least misleading.
The Small Catechism is very plain: "It is the true body and blood of our Lord Jesus Christ, under the bread and wine, for us Christians to eat and to drink, instituted by Christ Himself."
Under. Not "in," and not "with."
I suspect that we have morphed 2 parts of the catechism together, because in the explanation of baptism, we confess "It is not the water indeed that does them, but the word of God which is in and with the water, and faith, which trusts such word of God in the water."
Am I being overly picky on this? I don't know. But when we confuse these explanations, I suspect at the very least that we are being sloppy theologically. And when we are sloppy theologically, it is very easy to slip into some serious error.
Especially since these are not obscure parts of doctrine, but at the very heart and soul of our faith: the means of grace by which God grants us forgiveness of sins.
Words are important: "Hold fast the form of sound words, which thou hast heard of me, in faith and love which is in Christ Jesus" (II Timothy 1.13) And when we talk "differently" about the Lord's supper, I wonder if we are thereby confessing something different about that supper.