The world may understand causality, karma and innen. Understanding the soul/heart makes one aware of how this process of karma and causality works. The following is from the Ofudesaki:
Kono tokoro yorozu no koto o tokikikasu
Kami ichijo de mune no uchi yori3-46
Wakaru yo mune no uchi yori shiyan seyo
Hito tasuketara waga mi tasukaru 3-47
The first translation is the traditional translation by Tenrikyo Headquarters and the 2nd translation is word for word.
At this place, I shall teach everything.
Be single-hearted with God, and from your innermost heart. 3-46
Ponder from your innermost heart to understand.
Through saving others, you are saved. 3-47
At this place, I will teach everything about the world.
Become single hearted with God by what the innermost heart/soul brings forth. 3-46
From understanding what the innermost heart/soul brings forth, ponder!