Nichiren teaches that if the doctrine is flawed the faith of the believer will be flawed.

"Believing in the perfect teaching means to 'awaken faith through doctrine [of the Lotus Sutra] and make faith the basis of one’s practice.'”  -- Nichiren quoting the Maka Shikan of Tientai

If the doctrine is flawed, faith will be flawed. SGI's and Nichiren Shoshu's doctrines are flawed. Therefore, the members' faith is flawed. Believing that a living mentor or High Priest is required to attain Buddhahood is the most noxious poison for one's faith. Myoho renge kyo is the perfect doctrine. Shakyamuni Buddha and Nichiren Daishonin are the perfect teachers. We maintain perfect doctrine through the Sutra scrolls and writings of Nichiren Daishonin.