In the book Snow in August, what does Micheal Devlin learn about heroism in the course of the book?

The major characters of the novel meet during a snowstorm on their way to their respective churches. The Rabbi and Michael agree to help each other. Michael will give the Rabbi English lessons and the Rabbi will teach Michael Yiddish. Their language lessons evolve into a friendship. Michael learns the history of Judaism. Rabbi Hirsch learns the way of the Brooklyn Streets. However, their friendship does not come easy. They feel the pressure of prejudice felt against the Jews. This was an era following WWII and the Holocaust, an era in which Hitler had sought to annihilate the Jewish race and nearly succeeded. The persecution of the Jews in Europe during the mid 1940's seems to have had a contagious effect on other parts of the world, including America.  In spite of adversity, however, their friendship does not waver.
     The story is shadowed with impending doom. The main source of these problems is a local gang named The Falcons. The Falcons are the most racist and troublesome gang around. The leader and the main source of evil in the book is Frankie McCarthy, an anti -Semitic man. Frankie beats up the Jewish proprietor of a candy store, putting the old man in a coma. Michael and his friends have the bad luck to witness this. This is where the nature of heroism is explored. Michael knows that if he acts as a witness this gang will cause him physical harm. As the story unfolds it becomes certain that Frankie will come after him. Through the friendship of Rabbi Hirsch Michael learns that not reporting Frankie is as bad as committing the crime himself.It is a difficult and painful lesson about the nature of heroism. Finally, Frankie and his gang become too big a threat. The only thing that can help Michael is the Kabbalah Magic he learned from Rabbi Hirsch. Even though Michael and the Rabbi face great peril they overcome and defeat evil.