I’m a pretty new Lutheran and Ben probably knows more than me about what Lutherans believe.
But I’ve been reading Luther’s
Large Catechism and based on what Luther says there along with the words of the
Wittenburg Concordia, it appears to me that it is only in reception that the bread and wine become the true body and blood. And based on my reading of what Luther says in the Catechism, it depends on the person receiving them
believing that they are indeed the body and blood “given for you” and “shed for you” for the bread and wine to indeed become those things. But I could be wrong…