One did not need to believe in the Force to know right from wrong. Many who held no faith in the Force acted righteously, and he had known more than one sentient who had acted selfishly, even cruelly, and used belief to justify doing so.

I don’t need luck,” Chirrut said. “I have you.

There is more than one sort of prison, Captain," Chirrut said. "I sense that you carry yours wherever you go.