In His Holy Supper, Jesus gives His body and blood under the bread and wine, as He speaks "the Words of Institution" Sufficient discord on this doctrine prompted early Reformers to meet at Marburg in 1529 to hammer out their differences. The Swiss reformer, Ulrich Zwingli, argued that since flesh and spirit are incompatible, the presence of Christ in the Sacrament of Holy Communion can only be spiritual. Martin Luther declared that Christ's body and blood are truly present in the Sacrament. After Luther's death in 1546, two separate views of the Lord's Supper surfaced within the German Lutheran church. The Sacramentarians believed that Christ is not physically present, but is received by the Christian in the Holy Supper only by faith. These Lutherans were called Crypto-Calvinists (crypto means hidden or secret). John Calvin was a Reformer who had taken up the views of Zwingli. Orthodox Lutherans, like Luther, taught and believed in the real presence of Christ's body and blood in the Sacrament and declared there was a "sacramental union" between Christ and the Christian believer in the Lord's Supper. The Sacramentarians denied this sacramental union doctrine. This Formula of Concord Article, #7, describes key aspects of this controversy.