Hinduism is not a single creed but a vast family of traditions from India, with no founder, no central authority and no one required belief, so the first thing to know is that your friend's Hinduism is theirs: it may be devotional, philosophical, ritual, cultural, or all of these. Most Hindus believe in one ultimate reality, Brahman, which is beyond all description, and in many gods and goddesses (Vishnu, Shiva, the Goddess in her many forms, and others) who are understood variously as manifestations of that one reality, as distinct divine persons, or as the one God under many names; a devout Hindu may worship one of them as supreme. Vishnu is believed to descend into the world in avatars, of whom Krishna and Rama are the most loved; many Hindus will happily add Jesus to that list. The self (atman) is eternal and, in the most influential philosophy, ultimately one with Brahman; in devotional traditions it is eternally distinct from God and made for loving relationship with him. Life is governed by karma (every action bears fruit, in this life or the next) and by samsara, the cycle of birth, death and rebirth, from which the goal is moksha, liberation: release from the cycle, attained through knowledge, disciplined action, devotion, or meditative practice, over many lifetimes. The sacred texts are many: the Vedas and Upanishads as the most authoritative, the Bhagavad Gita as the most beloved, and the great epics, the Ramayana and Mahabharata. Dharma (duty, right order) shapes how one lives, and there is a deep tradition of religious tolerance, in which all sincere paths are held to lead toward the same goal. The caste system, though officially rejected in modern India and by many Hindus, still shapes some communities, and it is a sensitive subject to raise.
Where to read it for yourself
- Rig Veda 1.164.46: the truth is one; the wise call it by many names, the verse most often cited for Hindu pluralism
- Chandogya Upanishad 6.8-6.16: the teaching that the self is one with ultimate reality (tat tvam asi)
- Bhagavad Gita 4:7-8: Krishna descends in every age to restore righteousness, the classic statement of the avatar
- Bhagavad Gita 2:12-25: the eternal, indestructible self that passes from body to body
- Bhagavad Gita 9:22-34 and 18:65-66: devotion to Krishna, and his promise to free the devotee from all evils
- Bhagavad Gita 3 and 4: karma and action without attachment
- Brihadaranyaka Upanishad 4.4.5-6: as one acts, so one becomes: karma and rebirth