Q: Write a quote expressing the importance of the twofold revelation. Name the person who said it.
A: It is the criterion for whether or not one’s faith is true.
The ‘twofold revelation’ is the complete eradication of doubt in the truth of the self and the truth of the Vow; it is also called the ‘twofold revelation of the self and the Vow’ (Jp. kihō nishu jinshin). The Japanese word translated as ‘self’ is ki. The ‘revelation of the self’ is being made to know one’s own true nature with all clarity. The Japanese word translated as ‘the Vow’ is hō. The ‘revelation of the Vow’ is being made to know the veracity of the Primal Vow of Amida with all clarity.
The truth of the self and the truth of Amida’s Vow are both clearly revealed at the very same time when one is saved and embraced by Amida. This is known as the ‘unified twofold revelation of the self and the Vow of Amida’, or the ‘twofold revelation’ for short.
The Japanese word translated as ‘revelation’, jinshin, is written with Chinese characters meaning ‘deep’ and ‘belief’—but ‘deep belief’ is actually not what it means, since ‘belief’ implies the presence of doubt. To have something ‘revealed’ is to be made to know something without the slightest shred of doubt remaining.
Master Shinran expressed this as, “I know in truth,” and Master Rennyo said, “Now I clearly know.” Such knowledge has nothing whatever to do with efforts to swallow one's doubts and force oneself to believe.
(From You Were Born For A Reason Pt 2 Ch 11 Pg. 100)
Jinshin, the word rendered here as "revelation," is written with characters meaning "deep" and "belief," and yet it does not mean "deep belief." There is a difference between belief and the sure knowledge that comes from revelation. We "believe" because we doubt. When there is no possibility of doubt, we say instead that we "know" something. A person covered with terrible burns is unlikely to say, "I believe fire is hot." He knows very well from experience that it is so.
A principal who says, "I believe there is no bullying in my school," puts it that way because he suspects that there may in fact be bullying. Revelation is different. It means the receiving of knowledge beyond all shadow of doubt. That is why Shinran wrote, "I know in truth," and Rennyo, "Now I clearly know." Such knowledge has nothing whatever to do with efforts to swallow one's doubts and force oneself to believe. ‘True faith’ is the twofold revelation. The criterion that decides whether or not one’s faith is true is whether or not one has received the twofold revelation.
(from 2-20 of the doctrine book)