It was inevitable that Lutherans and Calvinists would split over the Sacraments and over the two natures of Christ. Luther would have no fellowship with anyone who did not acknowledge that the humanity and divinity of Christ was present in, with, and under the bread and wine. However, I don't think Luther really wanted Predestination to be a cause for separation because he avoided taking sides in presdestination disputes. After his death, Calvinist views became widely circulated among Lutherans. The Concordists (writers of the Formula of Concord) strongly refuted the Calvinist positions on limited atonement and double predestination as well as Calvinist sacramental views. The German churches that would not subscribe to the Formula joined the Reform church. Calvinists often say that the Lutheran Church deserted Luther's doctrine of predestination; whereas, Lutherans generally say that the Formula affirms Luther's position.