A great human revolution in just a single individual will help achieve a change in the destiny of a nation and, further, will enable a change in the destiny of all humankind.
Buddhism is action. One meaning of kyo of Nam-myoho-renge-kyo is action. Without action, we cannot say that we are practicing Nam-myoho-renge-kyo; it would merely remain a concept. Only through action are we able to truly gain the great benefit of the Mystic Law.