Rebbe Nachman- all evil is result of energy of imagination. Learning to see with inner understanding that everything is good. Every bad middah (quality) is an exchange of tov (good). Rebbe Nachman's story of the exchange of babies of maidservant's and the queen's. Rav Kook's Oros Ha'Teshuvah- everything is good. When Moshiach comes we will see that the world really is all good.