 In the early phase of Luther's career—until around 1536—he expressed concern for their plight in Europe and was enthusiastic at the prospect of converting them to Christianity through his religious reforms.Being unsuccessful in that, in his later career, Luther denounced Judaism and called for harsh persecution of its followers, so that they might not be allowed to teach.In a paragraph from his "On the Jews and Their Lies" he deplores Christendom's failure to expel them.