Jodo Shinshu (and Pure Land Buddhism in general) is often viewed as an inherently dualistic teaching, but upon examination and reflection I do not find such a position justified.
Shinran wrote quite clearly about this:
The supreme Buddha is formless, and because of being formless is called jinen. When this Buddha is shown as being with form, it is not called the supreme nirvana. In order to make us realize that the true Buddha is formless, it is expressly called Amida Buddha: so I have been taught. Amida Buddha is the medium through which we are made to realize jinen. – Letters of Shinran, ed Yoshifmi Ueda, pg. 30.
Amida Buddha as Upaya-Dharmakaya (or ‘Dharma-Body-as-Compassion’ also related to the Sambhogakaya) readily serves as an efficient affective focus. This formal aspect of Amida Buddha is both necessary and beneficial. The expedient means of the implied dualism serves to make establishing a deep and genuine rapport with reality (Tathata) that much easier.
Amida Buddha as Dharmakaya-Tathata (or ‘Dharma-Body-as-Suchness’) is the formless essence of Buddha Nature. Shinran Shonin has indicated that the “Dharma-Body-as-Suchness has neither color nor form; thus, the mind cannot grasp it nor words describe it.”
The ‘Other’ in other-Power is other only in relation to the limited and defiled mind of the evil person (bombu) for whom the Pure Land Path and the Primal Vow especially exist. It is not that Amida is an object ‘out there’ in the world. Nor are we to understand Amida to be a subject ‘in here’ within ourselves. Rather, Amida Buddha transcends the subject-object dichotomy. It is not a matter of Jodo Shinshu being dualistic or non-dualistic, but trans-dualistic —it is a middle-way going beyond the implied dichotomy.
T’ienT’ai Patriarch Chih I, in his “Ching-t’u Shih-i-lun” (or “Ten Doubts about Pure Land”) wrote:
The one Mind at the phenomenal level is not tainted by delusions of views and thoughts, and the One Mind at the noumenal level is not deluded by the supposed dualisms [of essence and form, nirvana and samsara, buddhas and sentient beings].’
So, let us not engage in contention and strife over the issue of whether or not Amida represents Dharmakaya or Samboghakaya. The two are not mutually exclusive: neither precludes the reality of —nor impedes the functioning of— the other. Indeed, without the Dharma-Body-as-Compassion (Upaya-Dharmakaya, also related to the Samboghakaya) the Dharma-Body-as-Suchness (Universal Buddha Nature or Dharmakaya-Tathata) could not readily be known to beings bound to the wheel of birth-and-death (Samsara).