 Most of Calvin 's statements on the Jewry of his era were polemical . For example , Calvin once wrote , " I have had much conversation with many Jews : I have never seen either a drop of piety or a grain of truth or ingenuousness – nay , I have never found common sense in any Jew . " In this respect , he differed little from other Protestant and Catholic theologians of his day . Among his extant writings , Calvin only dealt explicitly with issues of contemporary Jews and Judaism in one treatise , Response to Questions and Objections of a Certain Jew . In it , he argued that Jews misread their own scriptures because they miss the unity of the Old and New Testaments . 
