Who is a Jew?

"If you ask me who is a Jew, I will answer you: Who ever leads a valorous life is a Jew. In my eyes, a Jew is someone who is willing to be a hero, to always be in the minority, to be ready to fight. Part of what makes a jew special is his living a heroic life... it means someone fighting alone on a dark night as when Jacob was left alone and struggled with a man until dawn (Genesis 33:25) This represents the inner content of the Jew... that Jewish life means leading a life of valor."

Rabbi Yosef Dov Soloveitchik