Although we believed the doctrine of attainment of Buddhahood by all living beings because it was preached by the Buddha, it was difficult for some to fully accept it because of the lack of actual proof. However, it all became clear when the most important doctrine of becoming a Buddha with one’s present body was expounded in the “Devadatta” chapter in the fifth fascicle of the Lotus Sūtra. It is like turning black lacquer into white or purifying dirty water by putting a wish-fulfilling gem in it. The Buddha helped a small snake, who was actually a daughter of the dragon king, attain Buddhahood with her present body. From that moment, no one could have the slightest doubt about all men attaining Buddhahood. Therefore, the Lotus Sūtra expounds attainment of Buddhahood by all people after the model of enlightenment of women.
Sennichi-ama Gozen Gohenji, A Reply to My Lady Nun Sennichi