1. Oral and literary tradition that evolved over 3500 years.
Hinduism

2. An Overview of Hinduism
About 80 percent of India's population regard themselves as Hindus and 30 million more Hindus live outside of India. There are a total of 900 million Hindus worldwide, making Hinduism the third largest religion (after Christianity and Islam).
The term "Hinduism" includes numerous traditions, which are closely related and share common themes but do not constitute a unified set of beliefs or practices.
The ethnic, religious, and linguistic diversity of India's billion people has given rise to a diverse written and oral literary tradition that evolved over 3,500 years. Many of the languages of India, including Sanskrit, belong to the Indo-European family. Sanskrit, the language of literature, administration, and intellectual endeavor, entered India around 1500 B.C. with the nomadic Aryans. While Sanskrit is associated primarily with Hindu culture, the more popular Pali and Prakrit dialects were the preferred languages of Buddhists and Jains. Tamil, a language of south India belongs to the Dravidian language family. Interchange between north and south led to the development of both Sanskrit and Tamil literatures. With the arrival of Islam in the twelfth century, dynasties such as the Mughals introduced Islam and Arabic and Persian literatures to Indian literature and civilization. The onset of British colonialism in the seventeenth century positioned English as an important presence in Indian letters.

3. Hinduism – 4000 to 2500 BCE
Hinduism is thought to have gotten its name from the Persian word hindu, meaning "river," used by outsiders to describe the people of the Indus River Valley. Hindus themselves refer to their religion as sanatama dharma, "eternal religion," and varnasramadharma, a word emphasizing the fulfillment of duties (dharma) appropriate to one's class (varna) and stage of life (asrama).
Hinduism has no founder or date of origin. The authors and dates of most Hindu sacred texts are unknown. Scholars describe modern Hinduism as the product of religious development in India that spans nearly four thousand years, making it the oldest surviving world religion. Indeed, as seen above, Hindus regard their religion as eternal (sanatama).
While it is known that the Indus River Valley civilization flourished (ca. 3000–1500 B.C.), the writing of the period found in Mohenjo Daro and Harappa has not yet been deciphered. The first known writings, originating from the Aryans, are the Vedas. They are the primary scriptures of Hinduism and consist of four books of sacred hymns that are typically chanted by priests at ceremonies marking rites of passage. They are considered divine revelations and are often recited in the form of mantras, or sacred utterances.

4. Hinduism Foundations
Though believed by many to be a polytheistic religion, the basis of Hinduism is the belief in the unity of everything. This totality is called Brahman.
The purpose of life is to realize that we are part of God and by doing so we can leave this plane of existence and rejoin with God. This enlightenment can only be achieved by going through cycles of birth, life and death known as samsara.
One's progress towards enlightenment is measured by his karma. This is the accumulation of all one's good and bad deeds and this determines the person's next reincarnation.

5. Hinduism Foundations
Selfless acts and thoughts as well as devotion to God help one to be reborn at a higher level. Bad acts and thoughts will cause one to be born at a lower level, as a person or even an animal.
Hindus follow a strict caste system which determines the standing of each person. The caste one is born into is the result of the karma from their previous life. Only members of the highest caste, the Brahmins, may perform the Hindu religious rituals and hold positions of authority within the temples.

6. The Hindu Trimvirate or Timurti
3 Gods who are responsible for the creation, upkeep and destruction of the world
Brahma – 4 heads that came from the four Vedas, four arms , beard
Vishnu – preserver of the universe
Shiva – destroyer of the universe in order to recreate it
Why is Brahma not worshipped so much?
There are a number of stories in the Hindu mythology which point to why he is rarely worshipped. These are two of them.
The first view is that Brahma created a woman in order to aid him with his job of creation. She was called Shatarupa.
She was so beautiful that Brahma became infatuated with her, and gazed at her wherever she went. This caused her extreme embarrassment and Shatarupa tried to turn from his gaze.
But in every direction she moved, Brahma sprouted a head until he had developed four. Finally, Shatarupa grew so frustrated that she jumped to try to avoid his gaze. Brahma, in his obsession, sprouted a fifth head on top of all.
It is also said in some sources that Shatarupa kept changing her form. She became every creature on earth to avoid Brahma. He however, changed his form to the male version of whatever she was and thus every animal community in the world was created.
Lord Shiva admonished Brahma for demonstrating behaviour of an incestuous nature and chopped off his fifth head for 'unholy' behaviour. Since Brahma had distracted his mind from the soul and towards the cravings of the flesh, Shiva's curse was that people should not worship Brahma.
As a form of repentance, it is said that Brahma has been continually reciting the four Vedas since this time, one from each of his four heads.
A second view of why Brahma is not worshipped, and a more sympathetic one, is that Brahma's role as the creator is over. It is left to Vishnu to preserve the world and Shiva to continue its path of cosmic reincarnation.

7. Hinduism is not a homogeneous, organized system
Hinduism is not a homogeneous, organized system. Many Hindus are devoted followers of Shiva or Vishnu, whom they regard as the only true God, while others look inward to the divine Self (atman). But most recognize the existence of Brahma, the unifying principle and Supreme Reality behind all that is.

8. Sacred Writings of Hinduism
The first sacred writings of Hinduism, which date to about 1200 BC, were primarily concerned with the ritual sacrifices associated with numerous gods who represented forces of nature.
Vedic Texts – 4 Vedas and their supplements
The heroic age of Indian literature encompasses a wide range of writings. Ancient Tamil poetry valorizes love and war; Arjuna and Rama appear heroic to many because they balance the violence of warrior ways with compassion and self-restraint; Buddha's teachings of self-perfection elevated him to status as "superhuman hero-king." In all, the idea that moral and spiritual conquest is superior to conquest by the sword is an enduring motif of the time and one that was publicly endorsed by Emperor Asoka.
Hindus believe his powers of destruction and recreation are used even now to destroy the illusions and imperfections of this world, paving the way for beneficial change. According to Hindu belief, this destruction is not arbitrary, but constructive. Shiva is therefore seen as the source of both good and evil and is regarded as the one who combines many contradictory elements.

9. Vedas
Most Hindus respect the authority of the Vedas (a collection of ancient sacred texts) and the Brahmans (the priestly class), but some reject one of both of these authorities.
4 Vedas – Samhitas, The Brahmanas, The Aranyakas, The Upanishads
A more philosophical focus began to develop around 700 BC, with the Upanishads and development of the Vedanta philosophy.
The Vedas are the primary scripture of Hinduism and consist of 4 books of sacred hymns that are typically chanted by priests at ceremonies marking rites of passage.
Samhitas – most ancient consisting of hymns of praise to God, Brahmanas – rituals and prayers to guide priests, Aranyakas – worship and meditation, Upanishads – consist of mystical and philosophical teachings

10. The Upanisads
These Mystic Doctrines are the mystical and philosophical mediations by thinkers wishing to gain ultimate wisdom. Without negating the authority of the Vedas, the Upanisads proffer a different world view.
De-emphasizing the role of the ritualistic present in the Vedas, the Upanisads argue that the soul is the manifestation of a single divine essence.
The soul’s release comes from understanding the basic unity between the self and the universe.

11. Two Epics that express the core values of Hindusim are the Ramayana and the Mahabharatar
Though mythical in tone, the poems are based on actual historical events in north India. They are referred to as historical narratives and lay the foundation for Aryan rule in the Ganges River Valley.
Mahabharata – civil war between the Aryans – Bhagavad Gita
Ramayana – adventures in exile of Prince Rama of Kosala
Both epics emphasize dharma – the guiding principle of good human conduct and the force that holds the social, moral, and cosmic fabric of the universe together. Your duty as it is determined by your caste/role in society.
Dharma is the guiding principle of human conduct and preserves the social, moral, and cosmic integrity of the universe. It refers to sacred duties and righteous conduct, and is related to three other spheres that collectively govern an ideal life: artha (wealth, profit, and political power); kama (love, sensuality); moksa (release, liberation).

12. Bhagavad-Gita
700 verse Dharmic scripture that is part of the ancient Sanskrit epic Mahabharata
Contains a conversation between Pandava prince Arjuna and his guide Krishna (charioteer)
Conversations of philosophy based on the Upanishads

13. 4 Castes or Varna of Hindus
Brahmans – priests
Ksatriyas – warriors
Vaisyas – merchants
Sudras – laborers
All are bound by a set of duties or dharma; your fulfillment of these duties determines your place in the next life. You have multiple chances in multiple life cycles to get it right.
Only brahmans, ksatriyas, and vaisyas can work towards moksa. A woman’s dharma is related to her position as a wife, and she is thus given little space to define her own identity. While the social position of Hindus is determined at birth, making for a stratified society, many Hindu texts reflect ongoin power negotiations among the classes.

14. Karma
The belief that all beings are responsible for their own actions and their own suffering is known as karma.
In Hindu thought, the doer must bear the burden of these actions, and the soul is thus enmeshed in a perpetual cycle of life and death.

15. Triad of the gods
Ultimately, because Hinduism and its important texts such as the Bhagavad-Gita were able to synthesize tenets and ideas from the other religions, it was able to triumph in India.
Hindus also believe in a triad of gods—Brahma, the creator; Vishnu, the preserver; Shiva the destroyer—who are responsible for the lives of all creatures on a cosmic scale.
It is believed that worshiping Shiva or Vishnu eventually helps creatures escape from the cycle of karmic rebirth.

16. Hinduism’s Influence Today
In the 20th century, Hinduism began to gain popularity in the West. Its different worldview and its tolerance for diversity in belief made it an attractive alternative to traditional Western religion. Although there are relatively few western converts to Hinduism, Hindu thought has influenced the West indirectly by way of religious movements like Hare Krishna and New Age, and even more so through the incorporation of Indian beliefs and practices (such as the chakra system and yoga) in books and seminars on health and spirituality.
All actions good or bad have consequences.