"A very serious matter indeed"

"Within Buddhism, the Hinayana teachings will overthrow the Mahayana, the provisional Mahayana will overthrow the true Mahayana. In such cases, the Hinayana and provisional Mahayana will act as would non-Buddhist forces attacking the truth of Buddhism. But there will be other times when not the Hinayana or provisional Mahayana, but those dedicated to the Lotus Sutra* will act in such a way as to overthrow the Lotus Sutra and this will be a very serious matter indeed." -- Nichiren

*The Soka Gakkai, Nichiren Shoshu, Nichiren Shu, and Honmon Butsuryu Shu.