Hinduism is spreading around the world definitely, but not by conversion but by acceptance of Sanatana Dharma (Hindu’s dharmic way of life) by so many followers who won’t figure in any national census identified as Hindus!
Hinduism as a religion practised at a commoner level (worship of different God forms, formal temple worship, rituals etc) may not be spreading (except perhaps for Krishna Consciousness Movement by ISKCON) globally. Unlike abrahamic religions with one god and one holy book, Hinduism has so many facets. Hence there is is virtually no commonly acceptable mode of conversion to Hinduism. There is no ‘business’ of religious conversion to Hinduism ever existing in it. There is virtually no impetus in Hinduism to convert people of other religions.
Hinduism has such a wide base that there are umpteen paths within it for one to practice Hinduism. One path of Hinduism that is most appealing to many well educated westerners is Jyana Yoga (The path of Knowledge) and Vedanta (essence of Upanishads). Many non-Hindus with spiritual mindset get hooked Vedanta and Bhagavad Gita and they start getting right answers to their nagging doubts on spirituality not satisfactorily answered in their religions.
And there is the contribution of great spiritual masters and Avatara Purushas of Hinduism who have influenced a lot of non-Hindus to the spiritual paths open to them in Hinduism. There are countless followers of these masters across the world:
- Sri Ramakrishna Paramahamsa (1836–1886) and Swamy Vivekananda (1862–1902) — Sri Ramakrishna Paramahmsa was a rustic Bengali with little formal education who is considered a Divine Avatar that revived and re-validated practically all major paths and sects of Hinduism during British rule in India.His prime disciple Swami Vivekananda travelled to America and spread the wisdom of Vedanta to eager beavers in the west. At his prompting, a few the other disciples of Ramakrishna — Swami Saradananda, Swami Turiyananda, Swami Trigunatitananda and Swami Abedananda travelled to west and spread the message of Vedanta.
- Sri Ramakrishna Paramahamsa’s talks and discussions on multifarious aspects of Hinduism in the most simplified and easily digestible fashion were recorded and made available in a book The gospel of Sri Ramakrishna by his house holder disciple Sri Mahendranath Gupta. It was later translated into English by Swami Nikilananda. This is one magnum opus in Hindu spiritual literature that is being read and re-read by countless spiritual seekers cutting across all sects and sub-sects of Hinduism and all other religiously and spiritually inclined people across the the world, across religions.
Swamy Rama Tirta (1876–1906): He travelled Japan and USA in 1902 and influenced lots of Buddhists and Christians towards Hinduism. He spoke on practical Vedanta to Amrican audience. He was a true sanyasi in the sense that he travelled to USA and several other countries totally without carrying any money or luggage.