Every authentic spiritual path, every religion, every important philosophical system are all expressing in specific forms the fundamental effort of the human being towards Liberation. Consciously or unconsciously, everything in this Universe evolves faster or slower towards the same essential goal.
This Universe, even though it is gigantic, is just a part of an infinite existence. Restrained to a certain form which is subjected to space, time and determination (causality) we are perceiving parts of this Universe with our mind and senses (we can see it, feel it, touch it, hear it), we can draw it from our imagination, we can perceive its subtle force of influence and we can describe its specific principles and laws of manifestation.
The Universe that we perceive, on the background of which our existence unfolds, is reflected in our mind as being finite and limited. This reflection is, in essence, our mental creation. Beyond the limits of this mental creation, in other words beyond our usual mental possibilities, the laws and principles that operate in the objective Universe are having almost no correspondents. In this way, for the wise man it is clear that the fundamental law of action and reaction is perfectly plausible and becomes operative in the limits of "our Universe".
Beyond its limits our existence is not subjected anymore to this law, because the law of causality does not go beyond the borders of this Universe created by our mind. Thus, it is clear that our existence in this Universe is helplessly subjected to the law of causality (karma).
In this Universe, limited by our own perception, there is from a certain point of view, apparently no free-will, because will, being something that we try to know through our limited resources of "our Universe", is itself conditioned in its manifestation by space, time and causality. As such, everything that is subjected to the law of causality cannot be completely free because it is influenced by other factors and becomes in its turn a cause.
Nevertheless beyond the limited sphere of this Universe conditioned and limited by our mind, an Absolute Principle is manifested. The manifestation of this Principle is analogous to the manifestation of the human will. This Principle, being beyond the action of the law of causality, is absolutely free from all the laws of the Macrocosmic Harmony.
It is normal to conclude that in order to attain this complete Freedom we must be entirely capable of going beyond the borders of our limited and conditioned Universe. This going beyond is in fact a movement of alteration from our limited level of consciousness to the sphere of supreme eternal essential values, which are infinite and perfectly free. This movement of alteration which gives complete freedom requires a certain inner change based upon knowledge, understanding and elevation above everything that is limited, false, ephemeral in us (all these make our Ego).
For really transcending our Ego it is necessary to know its sphere of manifestation. All that generates new bonds in our being and fixates us in this Universe, represents the field and domain of action of the Ego. Our senses, thoughts, body, mind, attitudes, prejudices and concepts are all of them bearing, in a greater or lesser degree, the imprint of the Ego.
Karma Yoga, through altruistic and completely detached action, is teaching us how to suppress these tendencies that are permanently stretching their tentacles upon us and which are manifesting themselves through our basic selfishness. By gradually renouncing all forms of selfish attachments, by permanently and effortlessly controlling our mental processes, by acting completely detached and never being motivated by selfishness, by striving to offer in full sincerity all the results of our activities to the Divine, offering to Him permanently our small and ephemeral "Ego", by always being attentive and aware, open and yielding to all phenomena and states that are manifesting in and through us, we will begin to gradually attain this supreme Freedom, because from the moment we leave the Supreme Will to act through us and guide us in all we do, we are instantly getting out of the incidence of the laws of "our Universe" and therefore we resonate with the Supreme Harmony, which is God.
The great yogi Swami Vivekananda says the following in his book about Karma Yoga:
"Who can live or breath even for an instant if the Almighty does not want it?"
"God is the almighty Providence that is eternally active. Each force of manifestation belongs only to Him and it surrenders only to Him. God is ALL and He is present in ALL. We can only worship Him. Thus, do not strive to collect for yourself the fruits of your work, but perform detachedly the good for the sake of the good. Only then will you truly obtain the perfect detachment. Only then the terrifying handcuffs created by the senses and the mind will be broken and only then will our complete Freedom be re-attained. This Supreme Freedom is the essential goal of the Karma Yoga system."