‘Abdu’l-Bahá said: Disease is of two kinds:
material and spiritual.
Take for instance, a cut hand; if you pray for
the cut to be healed and do not stop its bleeding,
you will not do much good; a material remedy is
needed.
Sometimes if the nervous system is paralyzed
through fear, a spiritual remedy is necessary.
Madness, incurable otherwise, can be cured
through prayer. It often happens that sorrow
makes one ill, this can be cured by spiritual
means.