Nevin asserts that, “They [the two great Protestant Confessions] form altogether one of the most strange and interesting chapters, in the church history of the sixteenth century.” What is the substance of this interesting chapter in sixteenth century history? Here’s the rub:

The great point at issue in the controversy, as it now stood, was the mode simply of Christ’s mystical presence in the holy eucharist. The fact of a real communication with his true mediatorial life, the substance of his body and blood, was acknowledged in general on both sides. The rigid Lutheran party however were not satisfied with this. They insisted on a nearer definition of the manner, in which the mystery must be allowed to hold; and contended for the formula, “In, with, and under” indispensable to a complete expression of Christ’s sacramental presence. He must be so comprehended in the elements, as to be received along with them by the mouth, on the part of allcommunicants, whether believers or unbelievers. It was for refusing to admit these extreme requisitions only, that the other party was branded with the title Sacramentarian, and held up to malediction in every direction as the pest of society. The heresy of which it was judged to be guilty stood simply in this, that the presence of Christ was held to be, after the theory of Calvin, not “in, with and under” the bread, but only with it; not for the mouth, but only for faith; not in the flesh but only by the Spirit; not for unbelievers therefore, but only for believers. This was the nature of the question,  that now filled all Germany with conflagration. It respected wholly the mode of Christ’s substantial presence in the Lord’s Supper, not the fact of the mystery itself  (J. W. Nevin, History and Genius of the Heidelberg Catechism (Chambersburg, 1847), 29-30).