Anyone who believes that G-d runs the world knows that he does so via various ways & on many different levels. Rav Kook deals with these many venues how He transmits messages to us & analyzes the extent of the direct & indirect levels, including dreams (mine & those around me) sickness (mine & those around me), accidents, challenges etc. The question of "why bad things happen to good people" is based upon the mistaken & even childish thought that life is supposed to be smooth, as opposed to Judaism which sees life as challenges, some pleasant & others not, which are sent us as G-d's way of helping us grow, be independent & Godly. Many aspects of life have nothing to do with "reward & punishment", but are "wake-up calls" to analyze ourselves.
Rav Kook's optimism explains that what seems "bad" is just the "developing good", and takes issue with neo-paganism, Schoppenhauer and the school of pessimism.
Reward and punishment of the individual and nation in Israel and has pre-occupied many Jewish philosophers and Rav Kook suggests an innovative solution.