The teacher of the Dharma, chapter 10 (scripture 53) You need not enshrine my relics into the stupa, because my whole body already exists in there.
This teaches that believing the Lotus Sutra means believing the real
existence of the eternal Buddha Shakamuni. It is said that you need not
enshrine His relics (Shari) which are bones and ashes after cremation,
because it is taught by the Lotus Sutra that the Buddha is eternal
without appearance or disappearance and that His whole body is beside
those who believe the Lotus Sutra. That is to say, it teaches that you
need not enshrine His relics, because you believe the eternal Buddha who
is active having perfect body. The faith to the Lotus Sutra is to
believe the real existence of the Buddha. Although we make a wooden
statue of the Buddha or write the name of the Buddha, it is not the
intention of the Lotus Sutra that you worship the statue or the
character of name as the Buddha. In the Jyuryo chapter 16, it is said
that "I am here, not extinguished yet", in the Jinriki chapter 21, it is
taught that "In any place where the Lotus Sutra is enshrined, I am
always there." Therefore, it is the ideal of the Lotus Sutra that you
should advance to the awareness of the real existence of the Buddha.
Of course, making statue and picture of the Buddhait is not bad deed,
but devoting yourself to worship those substances formally is not the
intention of the Lotus Sutra. Because the Buddha said "You need not
enshrine my relics", also statues or pictures become the same object as
relics. If you stick to those portrayal objects and forget the eternal
Buddha, there is a possibility that you will fall into the idol worship.
There is the wrong sect which says "Only our Mandara Honzon enshrined
in the head temple is orthodox" and "Other Honzons which are not
directly connected with our Honzon have no benefit." They think it is
most important that Nichiren shounin wrote Mandara, but don't understand
why Nichiren shonin gave Mandara Honzon written by characters. If you
are asking persistently "Which is best one to worship, image of Buddha
or Mandara?", your study won't make progress to the consciousness about
the real existence of the original Buddha.