SGI versus Nichiren

"...To mix other practices with this Namu-myoho-renge-kyo is a grave error. A lantern is useless when the sun rises. How can dewdrops be beneficial when the rain falls? Should one feed a newborn baby anything other than its mother’s milk? No addition of other medicines is needed with a good medicine. Somehow this woman remained true to this principle, and continued to uphold her faith until the last moment of her life. How admirable, how worthy!" -- The Teaching for the Latter Day

For Jamie Lee Silver of the Chant for Happiness blog and SGI, its OK to practice Yoga, New Age, Astrology, Christianity, Islam, Kabbalah, Bahai, Ikedaism, and even Nembutsu along with Namu Myoho renge kyo.