If you want to explore the true depths of Reiki, then you need to learn Buddho. Without Buddho, there is no Reiki.

Are the Reiki symbols against religion? Where exactly do they come from, what do they mean, what do they do and how do they do it?

Reiki Jin Kei Do is a specific lineage and branch of the energy-healing discipline of Reiki. It contains the heart teachings of Usui Reiki.