The learned sages inform us that one takes his birth in India, the holy land of Bharata-varsa, after the gradual process of evolution through 8,400,000 species of life, including 900,000 aquatic species, 2,000,000 nonmoving species such as vegetables and hills, 1,100,000 germ and insect species, 1,000,000 bird species, 3,000,000 lower-animal species, and 400,000 human species.
The living spirit transmigrates from one species of life to another, and he is moving in that way for millions and millions of years within the hollow of the great universe. For this reason, the living spirit soul is described as all-pervasive.
Factually, also, in no country other than India have the great sages endeavored so much for the realization of the spirit self. It is admitted that in the Western countries the people have done their best to advance in the culture of material science, centered on the material body and mind.
But it is admitted, also, that notwithstanding all such advancement of material knowledge in the West, the people in general there are suffering the pangs of the poisonous effects of materialism because they have cared very little for the culture of spiritual science. Great thinkers in the Western countries must therefore look to the people of India if the message of Godhead, of genuine spiritualism, is to reach their ears.
Therefore, in Bhagavad-gita, Sri Krishna, the Personality of Godhead, has elaborately discussed karma-yoga, work with transcendental results, to douse the fire of materialism and brighten the future of humankind. There is a great difference between work for material gain and work with transcendental results. In many places throughout Bhagavad-gita, the Personality of Godhead mentions the word buddhi-yoga, or intelligence with transcendental results. And by this word buddhi-yoga we can also understand transcendental, devotional activities. For the Personality of Godhead says that He always favors His devotees by endowing them with the intelligence to perform devotional activities, so that at the end His devotees may attain to Him. In other places, also, it is said that God is attainable only through devotional activities. We can get rid of the results of our work only by the intelligent process of work with transcendental results.
Pure devotional activities are of one variety only. And how these devotional activities can be coordinated with our daily, active life has been explained in Bhagavad-gita. Coordinating such devotional activities with our daily activities is technically known as karma-yoga. The same devotional activities when mixed with the culture of knowledge are technically called jnana-yoga. But when such devotional activities transcend the limits of all such work or mental knowledge, this state of affairs is called pure transcendental devotion, or bhakti-yoga.
Ref: Message of Godhead (Chapter 2) authored by Srila Prabhupada (Founder – Acharya, ISKCON)