“If anyone preaches doctrines other than these, then even though he may be a Buddha, he is not to be trusted.
Thus one puts one’s faith in the Buddha who appears in the Lotus Sutra. Hence this is what I mean when I speak of basing one’s faith on a Buddha." -- Nichiren
In other words, study and practice the doctrines of the Lotus Sutra and Nichiren and base one's faith on Shakyamuni Buddha of the Original Doctrine.