Recently looking through Kenryo Kanamatsu great book on Shin Buddhism called: "Naturalness: A Classic of Shin Buddhism" I discovered a very simple yet profound explanation of the Nembutsu or the Name that Calls as Taitetsu Unno puts it.
"Namu-Amida-Butsu! It is in remembrance of the Original Vow of Amida and his Boundless Love for us that we recite his Blessed Name. It is to recollect that this island of sisolation has already been bridged over by him, and that he has not forgotten us, and will save us even now. It is to give our self up, and absolutely and without doubting, to trust (Namu) Amida Buddha (Amida-Butsu). Nay, it is not we that utter his name, but it is Amida who speaks to himself. It is his own utterance breathed in his breath. In the Anjin-ketsujo-sho (Tract on the Final Settlement of Peaceful Mind) written by an anonymous follower of the Pure Land Teaching, we read: "The Nembutsu means to think of (nen) Amida Buddha (Butsu), and to think of the Buddha is to remember that the Buddha has by the Active Power of his original Vow cut asunder for all beings the bounds whereby they are tied to birth-and-death, and that he has thus matured the condition for their Rebirth in the Recompensed Land where once entered they would never retrogade. When thinking of this merit accomplished by the Buddha, we rely single-heartedly upon the Original Vow, our threefold activity of body, mouth and mind is supported by the Buddha-substance and we are raised up to the state of enlightenment which constitutes Buddhahood."
The Vow of the Buddha has been revealed from the Primordial state. We are in touch with the Compassionate Grasp of Amida, but we see it not due to our blind passions. Simply relying solely upon Amida Buddha we are taken into a state of True Entrusting by the ever embracing and all-pervading power of Amida Buddha. This is the very substance of the Universe. The Interconnectedness of all things, as the Quantum Physist call "Entanglement" is the profound Unicity of All things in the all Compassionate Spirit. This Eternal Life of Amida is that which courses through all things in existence. We have our home in this, but due to our egocentricity we are caught in delusions and fall into hellish worlds. Even in this saha-world we are able to escape birth and death by the Loving Care of the One Life that Embraces all of us. No matter our race, sex, sexual preference, or social status.
In the Pure Land we are all Golden as if there is absolutely no difference between us from the Enlightened Mind of the Buddha. Each of us is unique in our own right just as the waves of the Ocean all have their shapes and sizes. That Ocean is that One Eternal Life of Amida Buddha. Returning to this is simply to Deeply hear the call from the Heart of hearts, the Spirit of spirits, the Buddha of Buddhas.
Namo Amida Butsu
"Just say the nembutsu and be liberated" Shinran Shonin
"However hard it may be to bid farewell to this world, when the conditions that bind us to this saha [samsara] realm run out, we are powerless to do anything as the final hour arrives and we are swept away to that Land." -A Record in Lament of Divergences