From the beginning,
Our trust that is placed in Amida
Is the mind
That does not arise from within.
True faith (shinjin) is not what we "get" in return for services rendered, whether saying the nembutsu, believing in the Buddha, or studying Buddhist doctrine. All such activities have their limits in self-power, and are in the final analysis calculative actions (hakarai) if they do not come naturally from the influence of Other-Power.
Rather, true faith is itself the heart that trusts to the utmost; it is Amida's own pure Bodhi-mind, and is consequently free from any shadow of doubt. As for where this faith is to be found, it is nowhere but the Name, which embodies the virtue directed to us for our going forth (to the Pure Land).
When confronted with the issue of how we can avail ourselves of this virtue-power, the answer is simply, "By hearing the Name." What do we hear? We hear the commanding call of the Tathagata's Vow: "Come to me just as you are!"
Since the compassionate Parent grasps me by the hand, I am born in the Pure Land just as I am. Because the "true and real Light" is presently shining throughout the ten quarters, my life-and-death problem is totally resolved. To realize this is to discover the unity of Savior and saved in Namo Amida Butsu.
Following such a realization, the feeling of "indebtedness to the Nembutsu" (ho-on nembutsu) will naturally arise.