The great diversity among the various Buddhist doctrines is a concern that emerges from attachment to self. In the Name [om amideva hrih, namu amida butsu, namo amitabhaya buddhaya] there is no doctrinal rationale.
If birth in the Pure Land were attained through doctrine, the question of which doctrine to accept would be appropriate. But birth does not depend in any way on doctrine. It depends on the Name.
Whatever spurious doctrine you may utter with your lips or accept in your mind, the Name is Dharma that does not depend on doctrine, nor on the mind. If we recite it, we will unfailingly attain birth in the Pure Land.
The Name possesses, by its own nature, the virtuous power to bring about birth. When we recite it, we will be born in the Pure Land, without any dependence on doctrine, without any dependence on the heart or mind, without any dependence on concepts.
For the practitioner who recites the Name, the body may remain in this defiled world a while longer, but the heart has already attained birth in the Pure Land.