"Intolerance is opposite to tolerance just as fire is to water. We can be tolerant of people who are ignorant and immoral. But we must be intolerant of people who have wrong views and slander the Lotus Sutra." -- Opening of the Eyes
We must be intolerant of wrong views. Nichiren says in On Practicing the Buddha's Teachings:
"The teachings of the Lesser Vehicle and of the provisional Mahayana were valid only for the people who lived during two thousand years after the extinction of the Buddha. We are living in the first five hundred years after the beginning of the Age of Degeneration. Now is the time to propagate the Lotus Sutra. The Lotus Sutra is the Pure Law, the Perfect Law, the One True Teaching. According to the Daijikkyo Sutra, in the first five hundred years after the beginning of the Age of Degeneration, people resort to fighting, and the right teachings of the Buddha are forgotten. In these years, the provisional teachings are mistaken for the true teachings. Now the teaching of the One Vehicle should be propagated and the provisional teachings criticized. What we should do is criticize wrong views."
Later in the same writing:
"I have appeared in Japan in this time of emergency by the order of the Buddha. I dare say that I am not fortunate. However, the order of the King of the Law is categorical. Therefore, according to the Lotus Sutra, I raise the army of the true teaching against the forces of provisional teachings, wear the armor of patience, take the sword of the Wonderful Law, bend the bow of the Revelation of the Truth, fix the arrow of honesty, ride in the white bullock-cart of equality, break the gate of provisional teachings, and hurl criticism at the followers of the Nembutsu, Shingon, Zen, Ritsu, and other sects. Some of them run away or withdraw, while others are captured and become my disciples. I will repeat the offensive. I will march on, although they are many and my friends are few."