The two crucial aspects of the Buddha's Awakening are the what and the how: what he awakened to and how he did it. His awakening is special in that the two aspects come together. He awakened to the fact that there is an undying happiness, and that it can be attained through human effort. The human effort involved in this process ultimately focuses on the question of understanding the nature of human effort itself.....what its powers and limitations are, and what kind of right effort (i.e., the Noble Path) can take one beyond its limitations and bring one to the threshold of the Deathless.
.....it made him realize the futility of the round of rebirth — that even the best efforts aimed at winning pleasure and fulfillment within the round could have only temporary effects. On the other hand, his realization of the importance of the mind in determining the round is what led him to focus directly on his own mind in the present to see how the processes in the mind that kept the round going could be disbanded. This was how he gained insight into the four noble truths and dependent co-arising — seeing how the aggregates that made up his "person" were also the impelling factors in the round of experience and the world at large, and how the whole show could be brought to cessation. With its cessation, there remained the experience of the unconditioned, which he also termed nibbana (Unbinding), consciousness without surface or feature, the Deathless.
.....All cultures are tied up in the limited, conditioned side of things, while the Buddha's Awakening points beyond all cultures. It offers the challenge of the Deathless that his contemporaries found liberating and that we, if we are willing to accept the challenge, may find liberating ourselves.
(source: The meaning of the Buddha's awakening by Thanissaro Bhikkhu)
Thus partial Awakening occurs when one feels passion and delight for the deathless as a dhamma; full Awakening, when that passion and delight are fully abandoned. Thus the teaching that all dhammas are not-self applies directly to this stage of the path, to remind the meditator that he or she should not regard the deathless with any form of passion or clinging at all. Once there is no passion for the deathless as a dhamma, full Awakening can occur.
As we will see in a passage below, the Buddha states that the meditator attains full Awakening by seeing the limits of all things conditioned, by seeing what lies beyond them, and clinging to neither.
.....while the Buddha describes it as a removing or doing away of all dhammas — and thus it goes beyond "all dhammas" and any possible statement that could be made about them. Once the meditator has done this, no words — being, not-being, self, not-self — can apply.
(source: The not-self strategy by Thanissaro Bhikkhu)
The actual and final refuge, embedded within the Dhamma as refuge, is Nibbana, "the deathless element free from clinging, the sorrowless state that is void of stain" (Itiv. 51). The Dhamma as refuge comprises the final goal, the path that leads to that goal, and the body of teachings that explain the practice of the path. The Buddha as refuge has no capacity to grant us liberation by an act of will. He proclaims the path to be travelled and the principles to be understood. The actual work of walking the path is then left to us, his disciples.
The proper response to the Buddha as refuge is trust and confidence. Trust is required because the doctrine taught by the Buddha runs counter to our innate understanding of ourselves and our natural orientation toward the world. To accept this teaching thus tends to arouse an inner resistance, even to provoke a rebellion against the changes it requires us to make in the way we lead our lives......we are prepared to recognize that our inherent tendencies to self-affirmation and grasping are in truth the cause of our suffering. And we are ready to accept his counsel that to become free from suffering, these tendencies must be controlled and eliminated.
(source: Refuge in the Buddha by Bhikkhu Bodhi)
The last two verses in this series introduce the end toward which this training points, which is also the goal toward which our lives should be steered: "Better than to live a hundred years without seeing the Deathless is it to live a single day seeing the Deathless. Better than to live a hundred years without seeing the Supreme Truth is it to live a single day seeing the Supreme Truth." If human progress is not to be reduced to a mere pageant of technological stunts aimed at pushing back our natural limits, we require some polestar toward which to steer our lives, something which enables us to transcend the boundaries of both life and death. For Buddhism that is Nibbana, the Deathless, the Supreme Truth, the state beyond all limiting conditions. Without this transcendent element we might explore the distant galaxies and play cards with the genetic code, but our lives will remain vain and hollow. Fullness of meaning can come only from the source of meaning, from that which is transcendent and unconditioned. To strive for this goal is to find a depth of value and a peak of excellence that can never be equaled by brazen technological audacity. To realize this goal is to reach the end of suffering: to find deathlessness here and now, even in the midst of this imperfect world still subject, as always, to old age, illness, and death.
(source: Better than a hundred years by Bhikkhu Bodhi)
our minds bear testimony in the ongoing contest between the wholesome mental factors and the unwholesome ones, between the upward urge for purification and the downward pull of the defilements. That this duality is not trivial is seen by the consequences: the one leads to Nibbana, the state of deliverance, the Deathless, while the other leads back into the round of repeated birth, samsara, which is also the realm of Mara, the Lord of Death.
To practice heedfulness is to take full account of these dualities with their profound implications. The heedful person does not aim at a choiceless awareness open to existence in its totality, for to open oneself thus is to risk making oneself vulnerable to just those elements in oneself that keep one bound to the realm of Mara. The awareness developed through heedfulness is built upon a choice — a well-considered choice to abandon those qualities one understands to be detrimental and to develop in their place those qualities one understands to be beneficial, the states that lead to purity and peace.
Both in our outer involvements in the world and in the mind's internal procession of thought, imagination and emotion, there continually spreads before us a forked road. One branch of this fork beckons with the promise of pleasure and satisfaction but in the end leads to pain and bondage; the other, steep and difficult to climb, leads upward to enlightenment and liberation. To discard discrimination and judgement for an easy-going openness to the world is to blur the important distinction between these two quite different paths. To be heedful is to be aware of the dichotomy, and to strive to avoid the one and pursue the other. As the Buddha reminds us, heedfulness is the path to the Deathless, heedlessness is the path of Death.
(source: A note on openness by Bhikkhu Bodhi)