It is stated in this sūtra that Nyagrodha became furious when his prayers were not answered. Ordinarily, those who get furious at the community deity will destroy themselves in this life and fall into evil realms in the next life. Nevertheless, Millionaire Nyagrodha was able to achieve his great wish of having a child as wise as Kāśyapa by getting very angry at the community deity and speaking ill of him. You should know that anger may be both good and evil. My remonstration with the Great Bodhisattva Hachiman today is anger for a good cause.

Kangyō Hachiman-shō, Remonstration with Bodhisattva Hachiman, Writings of Nichiren Shōnin, Doctrine 1, Page 271-272