Martin Luther by Martin E. Marty is a biography of the revolutionary theologian. The biography, as is typical with all biographies, examine not only Martin Luther's life but also his character and evolution as a historical figure.

The biography of Martin Luther can be seen as a chronological detailing of Martin the man, and Martin the figure. The general public usually views Martin Luther in the perspective of the latter, but what Marty details in the book is the flaws of Martin Luther the human being. For instance, he is seen as a man of the people, and yet he rubbed elbows with royalty and even advised some of them to suppress legitimate revolts.

The book shows how Martin Luther came to rebel against the Roman Catholic Church, as well as his disagreements with other Protestants. In examining Martin Luther, the theologian, the reader discovers that Martin Luther held extremist beliefs, and, in many cases, exhibits cognitive dissonance. He says or believes one thing, only to contradict himself through his actions. One of the examples of this is his admiration for Jewish scholars, but he supports their oppression and persecution if Jews did not convert to Christianity.

Insights such as these help paint a multidimensional portrait of a complex man; a priest whose rebellion against the Catholic elite was driven by his own extremist interpretation of biblical teachings.