Eucharistic prayer

Hello! I had a question about the consecration of the bread and wine. I noticed that the WELS churches that I go to consecrate the bread and wine with the Words of Institution. But I do not see anywhere in Scripture directly saying it should be done that way, and the Early Church Fathers seem to say that it must be done by a Eucharistic Prayer instead (for example, Saint Ambrose; De fide ad Gratianum 4.10.125). So, what is the proper way to consecrate it? Is it the Words of Institution that Christ said? Is it when Christ had given thanks over it before He distributed it (Matthew 26:26; Mark 14:22; Luke 22:19; 1 Corinthians 11:24)? And does this matter? Thank you for your time!

The Shepherd Under Christ, a pastoral theology textbook used at our seminary for many years, provides this explanation for the consecration of the elements.

“Essentially the consecration consists in speaking the words of institution over the visible elements. Its purpose is, first of all, to show that it is the pastor’s intention to carry out Jesus’ institution and to set the visible elements apart for use in the sacrament. It furthermore serves as a prayer that the Lord may do what He has promised, as a confession that the body and blood of Christ are present in the sacrament, and as an invitation to the communicants to appropriate Jesus’ promise by faith.

“Such a use of the words of institution in consecrating the visible elements is an ancient custom (cf 1 Cor 10:16), but the words are not to be considered a magic formula that affects a change in the elements. The presence of the body and blood does not depend on the simple repeating of the words but comes about through the gracious working of the Lord, whose promise is connected with the words. The real presence is therefore also not dependent on the faith of the man who speaks the words.”

If you would like to pursue the topic further, I would recommend reading The History and Use of the Eucharistic Prayer. It is available free from the Wisconsin Lutheran Seminary Essay File. One of the points of the paper is the following: “Luther’s liturgical reform of the Canon of the Mass was radical. Because the Canon strongly inculcates the view of the Mass as sacrifice, Luther in both his Formula Missae of 1523 and his Deutsche Messe of 1526 eliminated the entire Canon (Anaphora, Eucharistic Prayer) from the service with the exception of the bare Words of Institution which he retained. This practice has generally prevailed in Lutheranism to this present day.”