Shaiva sub-sects, Bhagavatism, Shaktism and Smartism, Sikhism's later Gurus and the Khalsa, and every major world religion practised in India.
Pashupata (North India, 2nd c. AD) — founded by Nakulisa; worships Shiva as Lord of Death; key texts the Pashupata Sutra and Ganakarika. Kashmir Shaivism / Trika — founded by Vasugupta after the 8th c., practises worship without mantra (using mudra), centred on the philosophy of Pratyabhijna (recognition). In Central India (via the Mahakaleshwar Temple, Ujjain): Mattamayura, Kalamukha, Kapalika, Aghora, Agamanta. In South India: the Nayanmars (63 saints) spread devotion through the Tevaram; the Shiva Advaita school (Srikantha); in Karnataka, the Veerashaiva movement (Basaveshwara); in Andhra Pradesh, the Aradhya tradition (Mallikarjuna Pandita). Sub-traditions of Shaivism also include Nath Panth (Gorakhnath, Hatha Yoga), Dashanami (disciples of Adi Shankaracharya), and Aghoris — the only surviving branch of the Kapalika tradition.
Bhagavatism, centred on Vasudeva Krishna, is first mentioned in the Chandogya Upanishad; the Bhagavad Gita carries its essence of Bhakti, Prapatti and Nishkama Karma. During the Gupta period it transformed into Vaishnavism, with Krishna understood as an avatar of Vishnu. The Greek envoy Heliodorus converted to Bhagavatism, commemorated by the Heliodorus Pillar at Besnagar. In Tamil Nadu, the Alvars (~12 saints) produced the Divya Prabandham; early sub-sects included Srivaishnava (Ramanujacharya) and Vaikhanasa (sage Vikhanasa).
Shaktism — worship of the Devi/Goddess as supreme feminine power — is popular in Bengal, Orissa and the North-East; principal goddesses: Durga, Manasa, Chandi, Kali. Smartism, based on the Puranas, worships five deities equally (Panchayatana — Shiva, Shakti, Ganesha, Vishnu, Surya, introduced by Adi Shankaracharya as the basis for later temple architecture) and accepts two forms of Brahman: Saguna (with attributes) and Nirguna (without).
The ascetic-based Shramana traditions include Jainism, Buddhism, Charvaka, Ajivika and Ajnana. Ajivika — founded by Makkhali Gosala (5th c. BC), centred on Niyati (absolute determinism, no role for karma); associated with Bindusara and mentioned in Ashoka's Pillar Edicts. Ajnana — radical scepticism, holding that ignorance is the best state since true knowledge is unattainable.
Guru Nanak (1469–1539) described God as one universal, genderless entity — Waheguru, Akal Purakh, Ek Onkar, Satnam. Three pillars: Naam Japna, Kirat Karni, Vand Chakna (embodied in the Langar); salvation requires no renunciation of household life. Guru Angad introduced the Gurmukhi script; Guru Arjan Dev compiled the Aadi Granth Sahib and was executed under Jahangir. Guru Hargobind transformed Sikhism from a spiritual cult into a martial tradition, symbolised by two swords (Piri and Miri — spiritual and temporal authority); built the Akal Takht. Guru Tegh Bahadur was executed in Delhi, 1675 (under Aurangzeb). Guru Gobind Singh transferred authority to the Guru Granth (scripture) and Guru Panth (community), founding the Khalsa with the Panj Pyare. The Khalsa observes the 5 Ks (Kaccha, Kesh, Kangha, Kirpan, Kara); "Singh" (men) and "Kaur" (women).
Zoroastrianism — founded by Zarathustra (~7th c. BC), centred on Ahura Mazda vs Angra Mainyu; sacred text the Zend Avesta. In India, adherents (Parsis) fled Iran around the 8th–10th c. AD, settling mainly in Mumbai, Goa and Ahmedabad; worship centres on fire (Atash Behram — 8 exist in India) and the "Towers of Silence" (Dakhma) practice. Judaism — traced to Abraham → Isaac → Jacob (Israel) → the 12 Tribes; key texts the Torah and Talmud. India hosts 5 Jewish communities: Cochin Jews, Bene Israel, Baghdadi Jews, Bene Ephraim (Telugu-speaking), and Bnei Menashe (Manipur/Mizoram).
Islam originated in 7th-century Arabia; the 5 Pillars are Shahada, Salat, Zakat, Sawm and Hajj; Shia recognise succession by bloodline (closest: Ali), Sunni recognise Abu Bakr. Indian reform movements: Faraizi (Haji Shariatullah), Tariqah-i-Muhammadiya (Sayyid Ahmad Barelvi), Ahmadiyya (Mirza Ghulam Ahmad), and the Aligarh Movement (Sir Syed Ahmad Khan). Christianity — believed introduced to India by Saint Thomas around 52 AD, giving rise to the Syrian Christian community; major branches Catholic, Protestant, Orthodox, with Roman Catholics the majority in India.
Sanamahism (Manipur, ancestor-worship), Ayyavazhi (Tamil Nadu), Sarnaism (Middle India, sacred groves), and the Baha'i Faith (traced to Persia, founder Bahaullah, known in India for the Lotus Temple — considered the fastest-growing religion in the world) round out India's remarkable religious diversity.
