The Lutheran confession on this score, correct me if I am wrong, is in the Real Presence of Christ in the Eucharist. The departure from Catholicism is in the rejection of the belief in transsubstatiation. I consider this a very serious breach from the Holy Tradition, which always spoke of the Body and Blood of Christ in the Eucharist as objective and not a product of the communicant's faith effort.
Over all, -- given the entirety of Luther's beliefs, including the mangling of the Old Testament Canon, discouragement of the monastic devotions, and the intrioduction of the innovative doctrines of Sola Fide and Sola Scriptura, -- I think you were right the first time, that Lutheran confession dates from 16c and not from the Early Church.
...the Body and Blood of Christ are truly present, and are distributed to those who eat the Supper of the Lord and they (Lutherans) reject those that teach otherwise.
It is the Lutheran belief that this article of faith was shared by the early Church.