Swami Satyananda: Most people must combine their daily work, in the form of karma yoga, with daily sessions of meditation practices. There must be acceptance, integration and understanding of both the inner and outer environments. For this reason, it is essential that each person with spiritual aspiration should practise introverting techniques, such as raja yoga, kriya yoga, pranayama and so on, combined with and supplemented by methods of harmonizing the interaction with the external surroundings, such as karma yoga.
Only in this way can one can start to effectively harmonize both the inner and outer worlds. Only in this way can one really start to tread the path and know the complete oneness of everything that exists, both internal and external. It is for this reason that karma yoga is so important, and why Swami Sivananda urged everyone to work and play in both the outer and inner world.