Here is part of what Luther had to say about the Sacrament of the Altar.
"It is the true body and blood of the Lord Jesus Christ in and under the bread and the wine which we Christians are commanded by Christ's word to eat and drink. As we said of Baptism that it is not mere water, so we say here that the sacrament is bread and wine, but not mere bread or wine such as served at the table. It is bread and wine comprehended in God's Word and connected with it."