Śākyamuni Buddha’s last words state that it is not non-Buddhist religions but Buddhists themselves that will destroy Buddhism, just as an insect living inside the body of a lion will eat up its flesh. In fact, some Buddhists destroy Mahāyāna teachings through Hinayana teachings while others extinguish the true Mahāyāna teachings by the provisional Mahāyāna teachings. These people, however, cannot exterminate the true Mahāyāna teaching of the Lotus Sūtra just as non-Buddhist religions cannot destroy Buddhism.

Hōmon Mōsaru-beki-yō no Koto, The Way to Refute the Evil Teaching, Writings of Nichiren Shōnin, Biography and Desciples, Volume 5, Page 150