It must not be forgotten that Luther knew Zwingli only as in some way connected with Andrew Bodenstein of Carlstadt. Carlstadt had professed to accept the theory of Honius about the nature of the relation of the Presence of Christ to the elements of Bread and Wine—saying that the latter were _signs_, and nothing more, of the former. A controversy soon raged in Wittenberg to the scandal of German Protestantism. Luther insisted more and more on the necessity of the Presence in the elements of the Body of Christ “corporeally extended in space”; while Carlstadt denied that Presence in any sense whatsoever. Luther insisted with all the strength of language at his command that the literal sense of the words of the institution must be preserved, and that the words “This is My Body” must refer to the Bread and to the Wine; while Carlstadt thought it was more likely that while using the words our Lord pointed to His own Body, or if not, that religious conviction compelled another interpretation than the one on which Luther insisted. The dust of all this controversy was in the eyes of the theologians when they met at Marburg, and prevented them carefully examining each other’s doctrinal position. In all essential matters Luther and Zwingli were not so far apart as each supposed the other to be. Their respective theories, put very shortly, may be thus summed up. Zwingli, looking mainly at the mediæval doctrine of the Mass, taught: (1) The Lord’s Supper is not a _repetition_ of the sacrifice of Christ on the Cross, but a _commemoration_ of that sacrifice once offered up; and the elements are not a newly offered Christ, but the _signs_ of the Body and Blood of the Christ who was once for all offered on Calvary. (2) That forgiveness for sin is not won by _partaking_ in a newly offered Christ, but by _believing_ in a Christ once offered up. (3) That the benefits of the work of Christ are always appropriated by faith, and that the atonement is so appropriated in the sacrament, whereby Christ becomes our food; but the food, being neither carnal nor corporeal, is not appropriated by the mouth, but by faith indwelling in the soul. Therefore there is a Real Presence of Christ in the sacrament, but it is a spiritual Presence, not a corporeal one. A real and living faith always involves the union of the believer with Christ, and therefore the Real Presence of Christ; and the Presence of Christ, which is in every act of faith, is in the sacrament to the faithful partaker. (4) That while the Lord’s Supper primarily refers to the sacrifice of Christ, and while the elements, Bread and Wine, are the symbols of the crucified Body of Christ, the partaking of the elements is also a symbol and pledge of an ever-renewed living union with the Risen Christ. (5) That as our Lord Himself has specially warned His followers against thinking of feeding on Him in any corporeal or carnal manner (John vi.), the words of the institution cannot be taken