Lotus Sutra reveals this truth, and one who embraces the Lotus Sutra will realize that hell is itself the Land of Tranquil Light.

Buddhism Day by Day

Wisdom for Modern Life by Daisaku Ikeda
Tuesday, September 10, 2013:

 

Neither the pure land nor hell exists outside oneself; both lie only within one's own heart. Awakened to this, one is called a Buddha; deluded about it, one is called an ordinary person. The Lotus Sutra reveals this truth, and one who embraces the Lotus Sutra will realize that hell is itself the Land of Tranquil Light. -Nichiren