Nichiren’s writings suggest two reasons why the Lotus Sūtra is “difficult to accept and to understand.” First, as Saichō had noted, the provisional teachings — those preached before the Lotus Sūtra — were expounded “according to the minds of others,” or in other words, the Buddha had accommodated them to the understanding of his listeners. In contrast, Śākyamuni preached the Lotus Sūtra “in accordance with his own mind,” revealing his own enlightenment. Nichiren took this to mean the Buddha’s insight into the mutual inclusion of the ten realms, or more specifically, the understanding that “our inferior minds are endowed with the buddha realm.” For many of Nichiren’s contemporaries, who believed that buddhahood was to be attained only after death in the Pure Land, this idea must have seemed deeply counterintuitive. “[Among the ten realms], the buddha realm alone is difficult to demonstrate,” he acknowledged. “But having understood that your mind is endowed with the other nine realms, you should believe that it has the buddha realm as well. Do not have doubts about this.”

Another reason why the Lotus Sūtra is “difficult to accept and to understand” is because those who propagate it may encounter antagonism. “People show great hostility toward this sūtra, even in the presence of the Tathāgata,” Śākyamuni declares in [Chapter 10]. “How much more so after the parinirvāṇa of the Tathāgata!” Although cast here in the form of a prophecy of what will happen after the Buddha’s demise, this passage may point to opposition from the Buddhist mainstream encountered by the early Lotus community. For Nichiren, it foretold the hardships that he and his followers encountered in spreading the Lotus Sūtra. Writing from his first exile, to the Izu peninsula, he confessed, “When I first read this passage, I wondered if things would really be so terrible. But now I know that the Buddha’s predictions do not err in the slightest, especially since I have experienced them personally.” For Nichiren, this sūtra passage carried a double legitimation, both of the Lotus Sūtra to which he had committed his life and of his own practice in upholding and propagating the Lotus. The passage is cited nearly fifty times in his extant writings.

At the same time, Nichiren saw the “difficulty” of embracing the Lotus Sūtra as pointing, not merely to the inevitability of hardships, but also to a guarantee of buddhahood. “To accept [the Lotus Sūtra] is easy,” he wrote. “To uphold it is difficult. But the realization of buddhahood lies in upholding faith. Those who would uphold this sūtra should be prepared to meet difficulties. Without doubt, they will ‘quickly attain the highest Buddha path’.”