Around what main themes does Michelangelo base his art as noted in the biography, Michelangelo?

Michelangelo's art concerns Christian themes; the artist's strong religious faith inspired some of his most powerful works. Ripley objectively and accurately depicts Michelangelo as a man grounded in Christian belief and culture. Her biography does not focus on the specifics of Christianity but instead explores the universal notion that profound faith or devotion to an ideal can find expression through artistic genius.