"A Calvinist can only regret that the Lutheran churches retained the one doctrine on which Luther disagreed with Zwingli and Calvin, and discarded, under the influence of Melanchthon, the many doctrines on which there was complete or almost complete agreement at the beginning."
Dr. Gordon H. Clark. Philippians. (Hobbs: Trinity Foundation, 1996), p. 62.
Post script: Dr. Clark is of course referring to the sacrament of the Lord's supper as the doctrine where Calvinists and Lutherans disagree. It's a bit more complicated than that, of course. The communication of the divine attributes to the human nature of Christ would end up in the monophysite error. But the point of Dr. Clark's comment is that Luther did not disagree with the Calvinists and Zwinglians on predestination of the elect and the reprobate. Modern Lutherans are irrationalists at best and mostly agree with the Arminians on many things.