We should never imagine that the perfection and the wonderful inner realisation made possible through the Karma Yoga system are easy to attain. Even the correct intellectual understanding of its rules and of their correct application is not easy at all. Kåñnasays in Bhagavad Gita: "Regarding what detached action and inaction are in fact, even sages are sometimes uncertain and some of them are mistaken. We must understand well the concept of detached action, wrong action and inaction. A great wisdom is necessary here because the path of actions is often very complicated".
Sri Ramakrishna regularly talks about the difficulties in the practice of Karma Yoga: "Nishkama karma (the action that is detached of the selfish desire for its fruits) is very difficult" (Teachings of Ramakrishna). "The total unselfish action is very difficult, especially in our time. To act with no egotistical attachment is extremely difficult". And Swami Vivekananda observes with a certain disappointment: "The person who can act completely detached for five days, or even for five minutes, with no egotistical motive whatsoever, without thinking at all to the future, to the rewards of Heaven, to gratification, to punishments or to any other things of the sort, will instantly become a powerful spiritual giant." (Practical Integral Yoga). Sri Ramakrishna told his disciples to think as follows: "I imagine that I accomplish my deeds with detachment, but I do not know for sure to what extent this is an illusion and if I don’t actually act somewhat attached. I do charity acts not knowing if in this way I am trying in fact to step forward in the eyes of people." (Teachings of Ramakrishna). And Sri Aurobindo says: "Karma Yoga is a rapid path, simpler than the Yogic meditation, with the condition that the mind is not fixated upon Karma, but exclusively upon the Divine" (Integral Practical Yoga).
Ma Ananda Moyi adds: "The action that is totally consecrated to God is much more valuable than the action performed under the impulse of our own desire. The former brings about the divine fusion that will lead to Enlightenment, and the latter has as goal the selfish pleasure that will lead to more and more experiences in this world. The only true action is the one who reveals the eternal fusion between the human being and God; the other actions are useless, undignified to be called ‘actions’ and because of that we can say that they are not at all actions". (Teachings of Ma Ananda Moyi)