While the method of stoic acceptance relies on the power of the will, and the method of indifference relies on the power of knowledge, the method of submission or surrender has its roots in the way of devotion. All three represent paths toward achievement of equality in the nature to prepare for and begin to take on the spiritual consciousness of the Divine in the being of the seeker.
Sri Aurobindo notes: “The third way is that of submission, which may be the Christian resignation founded on submission to the will of God, or an unegoistic acceptance of things and happenings as a manifestation of the universal Will in time, or a complete surrender of the person to the Divine, to the supreme Purusha. … If it is pushed to the end, it arrives at the same result of a perfect equality. For the knot of the ego is loosened and the personal claim begins to disappear, we find that we are no longer bound to joy in things pleasant or sorrow over the unpleasant; we bear them without either eager acceptance or troubled rejection, refer them to the Master of our being, concern ourselves less and less with their personal result to us and hold only one thing of importance, to approach God, or to be in touch and tune with the universal and infinite Existence, or to be united with the Divine, his channel, instrument, servant, lover, rejoicing in him and in our relation with him and having no other object or cause of joy or sorrow.”
As with the other paths, there are obstacles along the way: “Here too thre may be for some time a division between the lower mind of habitual emotions and the higher psychical mind of love and self-giving, but eventually the former yields, changes, transforms itself, is swallowed up in the love, joy, delight of the Divine and has no other interests or attractions. Then all within is the equal peace and bliss of that union, the one silent bliss that passes understanding, the peace that abides untouched by the solicitation of lower things in the depths of our spiritual existence.”
Sri Aurobindo, The Synthesis of Yoga, Part Four: The Yoga of Self-Perfection, Chapter 12, The Way of Equality, pp. 685-686