In being true to the small voice within, you are being of service to others and to the world in the most profound way possible. You cannot know where that voice will take you, but in being willing "to save the only life you could save," you are affirming one of the deepest and most sobering truths of all: no one else can ever walk your journey for you. You alone can respond to your call.
The inner self is as secret as God and, like God, it evades every concept that tries to seize hold of it with full possession. It is a life that cannot be held and studied as object, because it is not "a thing". It is not reached and coaxed forth from hiding by any process under the sun, including meditation. All that we can do with any spiritual discipline is produce within ourselves something of the silence, the humility, the detachment, the purity of heart and the indifference which are required if the inner self is to make some shy, unpredictable manifestation of presence.