In Shin Buddhism, Dharma is the Buddha's teaching, which is expressed as the Primal Vow of Amida Buddha. The Primal Vow stated in the Larger Sutra goes,
"If, when I attain Buddhahood, the sentient beings of the ten quarters, with sincere mind entrusting themselves, aspiring to be born in my land, and saying my Name perhaps even ten times, should not be born there, may I not attain the supreme enlightenment. Excluded are those who commit the five grave offences and those who slander the right dharma."
The Primal Vow has been the core of the saving of all suffering people in the world.
Shinran Shonin realizes it as follows:
"Shakyamuni Tathagata appeared in this world
Solely to teach the oceanlike Primal Vow of Amida."
"The masters of India in the west, who explained
the teaching in treaties,
And the eminent monks of China and Japan,
Clarified the Great Sage's true intent in appearing
in this world,
And revealed that Amida's Primal Vow accords
with the nature of beings."
Amida's Primal Vow that was revealed by Shakyamuni went on to be experimented and verified by the seven Pure Land masters (Nagarjuna, Vasubandhu, T'an-luan, Tao-ch'o, Shan-tao, Genshin, and Genku) , and then by Shinran, each in their own historical times.
Such is the tradition of the nembutsu coming from the Primal Vow that Shinran reaffirms it as follows:
"If Amida's Primal Vow is true, Shakyamuni's teaching cannot be false. If the Buddha's teacing is true, Shan-tao's
commentaries cannot be false. If Shan-tao's commentaries are true, can Honen's (Genku's) words be lies? If Honen's words are true, then surely what I (Shinran) say cannot be empty."
(Tannisho: A Record in Lament of Divergences)
Thus we would like to know what life Shinran lived and what he taught in the other section.