The Lord’s Supper was very important to Luther his entire life, because God’s promises and the bond with Christ became concrete for him in the bread and wine. He believed that Christ was bodily present in them, due to the words of Matthew 26: 26 and 28: ‘This is My body’ and ‘this is My blood’. At the same time the Lord’s Supper was an important focal point in not only his fight with Rome, but also in discussions inside the reformation camp.
In a sermon about the right use of the Lord’s Supper, from 1518, Luther says that needing the Lord’s Supper is the most important condition into receiving it. Interestingly, in 1519 he hesitated to say that Christ is bodily present in the elements. From 1520 on, though, it is clear to him that the words of Matthew 26 should be understood literally. The declaration that the wine is blood and is shed ‘for the remission of the sins’ create and seal real forgiveness for whoever receives that promise in faith. And whoever does not believe, receives Christ to their own judgement.
Luther posited, against Rome, that Christ does not remain present in the host after the Lord’s Supper, and that the host can not be worshipped. He also denies the notion that the Lord’s Supper is a repetition of the sacrifice of Christ, because that attitude would mean that man has something to bring to God.
When, in the twenties, Luther again had to think about the liturgy, big differences rose to the surface inside the reforming camp. Luther turned sharply against the ideas of Karlstadt and Zwingli, who suggested that the Lord’s Supper was a memorial meal, and that the words of institution are meant not literally, but figuratively (‘This signifies My body’). According to Luther, that meant a violation of the plain meaning of the Scriptures and furthermore the concrete presence of Christ through faith was removed. In his Vom Abendmahl Christi. Bekenntnis, the most elaborate book he wrote on the issue, he opined that Christ was bodily omnipresent (‘ubiquity’). That was necessary to apprehend the concrete presence of Christ in the bread and wine, without having to return to the Roman-Catholic doctrine of transubstantiation.
However, his Reformed opponents wanted to clarify their position, that only Christ Himself and not the elements of bread and wine provided salvation. They were also afraid of all kinds of superstitions around the Lord’s Supper. Attempts to reconcile the camps (especially the Marburg Colloquy) ended in failure. Post Luther, the Lord’s Supper has remained an important point of difference between the Lutheran and the Reformed.
- Sermo de digna praeparatione cordis pro suscipiendo sacramento eucharistiae  (WA 1, 329-334);
- Sermon von dem hochwürdigen Sakrament des heiligen wahren Leichnams Christi und von den Bruderschaften  (WA 2, 742-758);
- Sermon vom Neuen Testament  (WA 6, 353-378);
- Formula missae et communionis  (WA 12, 205-220);
- Von Anbeten des Sakraments  (WA 11, 431-456);
- Sermon von dem Sakrament des Leibs und Bluts Christi wider die Schwarmgeister  (WA 19, 482-523);
- Das diese Worte Christi ‘Das ist mein Leib etc.’ noch fest stehen wider die Schwarmgeister  (WA 23, 64-283);
- Vom Abendmahl Christi. Bekenntnis  (WA 26, 261-509).