Only when one understands all this clearly and believes in it can the Law manifest its power and the Buddhas and bodhisattvas bring benefit to the people. To illustrate, in kindling a fire, three things are needed: a good piece of steel, a good flint, and good tinder. The same is true of prayer. Three things are required— a good teacher, a good believer, and a good teaching— before prayers can be effective and disasters banished from the land.
A good teacher is a priest who is free from any fault in secular affairs, who never fawns upon others even in the slightest, who desires and is satisfied with little, and who is compassionate; a priest who reads and upholds the Lotus Sutra precisely as it teaches and also encourages and leads others to embrace it. Such a priest the Buddha has praised among all priests as the finest teacher of the Law.
A good believer is one who does not depend upon persons of eminence or despise those of humble station; who does not rely on the backing of superiors or look down on inferiors; who, not relying upon the opinions of others, upholds the Lotus Sutra among all the sutras. Such a person the Buddha has called the best of all people.
As for a good teaching, the Buddha has told us that this sutra, the Lotus, represents the foremost among all doctrines. Among all the sutras the Buddha “has preached,” among those he “now preaches,” and among those he “will preach,” this sutra is designated as foremost, and therefore it is a good teaching.
~Nichiren Daishonin, WND, page 880