HINDU : Being Hindu is a personal notion, rather than a social notion.

Hindu! I'm Hindu, you are Hindu, but our perception of being Hindu is different.

Even, my perception of Hindu is not the same from the very beginning. It keeps changing with age, or truly, with knowledge. Generally, we try to fix it with religion. Hardly one succeeded in it, but for the short term.

The term ‘Hindu' first emerged in Persia, which denotes ‘people beyond river Indus', that’s Sindhu. And the land beyond Indus is called Hind. So, the people of Hind are Hindu. As like, the people of India are Indian. It was used in a geographical context. A name given by a foreigner doesn’t change the entity being named. It is even more apt because it demarcates the characteristics, directly or indirectly.

As time passes, the word Hindu seen a great evolution. From the people of Hind to Followers of Vedas and far later Idol worshipper. Its meaning becomes geographical to religious. 

In general, Being Hindu means following Hindu practices or Hinduism, it is somehow incomplete. It is about different philosophies at different periods by hundreds of philosophers. In prevailing, the majority of Hindus have nothing to do with these philosophies. 

These philosophies form the basis of Hindus' beliefs. Some of the major philosophies can be divided into Āstik (do believe in Vedas) and Nāstik (don't believe in Vedas). These are-

Āstik Philosophy 

Sāmkhya -  by Sage Kapil

Eliminate Physical and Mental Pains for receiving liberations, Nontheistic Dualism

The dualistic philosophy of Purusa and Prakrti; according to many followers of Sankhya philosophy, there is no such God exists. For them, Purusa is sufficient to inspire the unconscious Prakrti to manifest herself in the form of the universe. However, a section of Sankhya philosophers believed in the existence of a Supreme Being who guides Prakrti independently accordingly to His will. The extent of mayic creation and Divinity beyond that; it tells that the entire mayic creation is worth discarding and only the Divinity is to be attained because that is the only source of Bliss.

Yoga - by Sage Patanjali

The practice of Meditation and Samadhi for Renunciation, Self Discipline for Self Realization

Explain the practical process of heart purification which may qualify the individual to experience the absolute Divine. The word Yoga is derived from the Sanskrit root Yug, which meant "TO UNITE". The yoga system provides a methodology for linking up individual consciousness with the Supreme Being. Various schools of yoga systems are Bhakti Yoga, Jnana Yoga, Karma yoga, Ashtanga Yoga (practical application of Sankhya Philosophy), etc.

Nyāya - by Sage Gautam

Logical Quest of Supreme, Phases of Creation, Science of Logical Reasoning

It is a logical quest for God, the absolute Divinity. It tells that the material power “Maya”, with the help of God, becomes the universe. Nyaya Darshan is based on establishing the fact that only the Divinity (God) is desirable, knowable, and attainable, and not this world. Nyaya philosophy is primarily concerned with the correct knowledge to be acquired in human life and the means of receiving this knowledge.

Vaishesika – by Sage Kanad

Science of Logic, Futility of Maya, Vedic Atomic Theory

It aims to receive happiness in this life (by renouncing worldly desires) and finally to receive the ultimate liberation (through the attachment of the true knowledge of the Divine). According to this school of philosophy, there is no creation or annihilation but rather an orderly and morally systematized composition and decomposition of matter. Atoms (not we studied in our elementary science) are the smallest particle that exists in the universe and is eternal in nature. 

Karma Mimāmsā -  by Sage Jaimini

Poorv Mimamsa explaining the Vedas are eternal and Divine; Elevation Through the Performance of Duty

The word Mimamsa means to analyze and understand thoroughly. The main goal of the Karma-Mimamsa philosophy is to provide a practical methodology for the utilization of the Vedic religion (dharma) for the satisfaction of the urges for wealth (artha) and sensual pleasure (kama). It examines the teachings of the Vedas in the light of karma rituals. The Karma-Mimamsa system is called Poorva-Mimamsa, which means the earlier study of the Vedas. Karma-Mimamsa is to be taken up by householders.

Vedantā - by Sage Ved Vyas

Uttar Mimansa (Brahma Sutra) explaining the divine nature of Soul, Maya, and Creation; Conclusion of Vedic Revelation

It reveals this secret that God is absolute Divinity and absolute Bliss, and He is Gracious. So desire, fully remember Him, and with His Grace experience His absolute Blissfulness forever. Vedanta examines the Vedas teachings in the light of transcendental knowledge. Vedanta is called Uttara-Mimamsa, which means the later study of the Vedas. Vedanta is reserved for those who have graduated from household life and taken up the renounced order (sannyasa).

Nāstik Philosophy

Charvarka - It is characterized as a materialistic and aesthetic school of thought. Accepted direct perception as the surest method to prove the truth of anything. Insists on joyful living.

Also known as Lokayata, Charvaka is a materialistic school of thought. Its founder was Charvaka, author of the Barhaspatya Sutras in the final centuries B.C.

Buddhism - It is a system of beliefs based on the teachings of Siddhartha Gautama. Buddhism is a non-theistic philosophy whose tenets are not especially concerned with the existence or non-existence of God.

Jainism - Already in existence by 6th century B.C, it was revived by Mahavira, the 24th Jain Tirthankara. According to Jainism, Nirvana or liberation is obtained through three jewels: Right Philosophy, Right Knowledge, and Right Conduct (Tri-ratna). Right conduct implies 5 abstinences: not to lie, not to steal, not to strive for luxury and not to strive for possessions, not to be unchaste, and not to injure (Ahimsa).

Ājīvikā - A related philosophy that some classify under the heterodox system is Ajivika Philosophy. The Ājīvikas may simply have been a more loosely-organized group of wandering ascetics (shramanas or sannyasins). Some of its prominent figures were Makkhali Gosala and Sanjaya Belatthaputta. 

There are many more philosophies because being Hindu means finding his/her path to attain the ultimate truth. They have different views, still, respect each other.

More interestingly, the total number of Hindu philosophies may be as large as 1 billion, equal to the total Hindu population. Or even 7 billion.

Many of you may have objections to Jainism and Buddhism followers being called Hindus. 

Buddha and Mahavira were essentially few of the sages striving for knowledge and bringing succor to the masses in their own style. Before Buddha there were hundreds like him, after Buddha, there were hundreds like him. Shankracharya, Kabir, Nanak, Eknath, Jaydeva, Ravidas, Ramanuja, Chaitanya Mahaprabhu...many many.

In general, Common Hindus have very little concern about these philosophies. They just followed these teaching, start worshiping god in different forms or even formless. It gives rise to two aspects of god. Sagun, with the attribute, and Nirgun without the attribute. 

Saguna bhakti is the practice of devotion to God in form. God in form exists in all physical presence from the planet, the moon, the sun to all objects and beings in nature. The devotion to God in form recognizes that the appearance of God seems limited by form; however, the presence of God is unlimited. 

Nirguna bhakti is devotion to and worship of the Divine as formless. The term comes from the Sanskrit, nir, a prefix meaning “without”; guna, meaning “qualities” or “properties,” and bhakti, which means “devotion” or “faithfulness.”

Guru Nanak, the first Sikh Guru and founder of Sikhism, too was a Nirguna Bhakti Saint and social reformer. He preached the unity of God and condemned formalism and ritualism of both Islam and Hinduism. Guru Nanak's gospel was for all men. He proclaimed their equality in all respects.

Many other Saints like Kabir, Tulsidas, Meera, Chaitnya Mahaprabhu, etc worshiped his god. 

Today, there are many types of spiritual trends, many sects in India. Among social groups, Brhamkumari, Aryasamaj, Sanatani, if one counts it will be thousands. If one goes by personal beliefs then there are 1 billion sects because there are 1 billion Hindus. 

Some people, consider these sects as different from Hinduism. That's not true. As an example, Chinese society has seen several influential thinkers, but they did not call it a religion of Confucious or Buddha or religion of Lao Tzu, they remained Chinese.

Sawarkar, Vivekanand, and many true Hindu intellectuals of modern India never found Buddha, Mahavira, and Guru Nanak as separate from Hindu.

Sawarkar said in his book 'Hindutva', Sawarkar himself didn't believe in the existence of God. For Sawarkar his belief was merely a personal opinion, which existed in harmonious company with 330 million other personal opinions of all Hindus (Hindu population in 1940 was 330 million).

The Sangh Parivar, the modern Hindu nationalist coalition in India, often includes Sikhs, Buddhists, followers of Ayyavazhi, Jains, Sarnaists, and all other religions prominent in India. This particular brand of Hindu identity was coined in the 1920s, though it increasingly is promoting following the Vedas as the mark of a Hindu.

According to my, the essence of being Hindu is not worshiping one of the pantheons, but striving to establish Dharma/ethical living, striving for wisdom, truth with the same vigor as our ancient rishis did.

In Hindu-ism, the ism of Hindus as intellectual property, which ancient sages and today's intellectuals created and updated for the moral well-being of Humanity. Just like science, arts, literature, etc.

Being Hindu practically means peaceful co-existence. You are free to select your mode of worship & all others will respect your choice. Neither Hindus nor Hindu Gods, ever force you to worship only one form of God. You worship in your way & let others worship, in their way.

You can believe in supreme power and be a Hindu, and you may not believe in a God and still be a Hindu.

So, who is Hindu? One who-

Believe in a divine being, is Hindu.

Don't believe in a divine being, is Hindu (Charvaka).

Believe in God, is Hindu.

Don't believe in God, is Hindu(Samkhya).

Believe in Vedas, is Hindu (Āstik).

Don't believe in Vedas, is Hindu(Nāstik).

Believe in idol worship, is Hindu (Sagun).

Don't believe in idol worship, is Hindu (Nirgun).

Believe in oneness, is Hindu (Advaita).

Don't believe in oneness, is Hindu (Dvaita).

Believe in rebirth, is Hindu.

Don't believe in rebirth, is Hindu (Lingayat).

Even, if you don't believe in any of these, you are Hindu (Ajivika).

A Hindu is someone who believes in the Good for all, is conscientious, empathic, and prioritizes humanity above all else.

Those who do not dominate their subordinates in any department, those who believe in personal wisdom, and value each being in their way as the instance of almighty, are truly Hindu.

A Hindu is a person who considers everyone as his family and believes firmly in the doctrine of Vasudhaiva Kutumbakam.

Being Hindu is not a social concept, it is an individual concept. One is free to follow his/her way of life, and at the same time, respect another way of life.

Hindus worship different gods and deities. Besides this, they worship different sage & saint, plant & animals, and so. 

Thus, Being Hindu is a personal belief that existed in harmonious company with other beliefs.

 Hindu wisdom can offer soothing breeze in this period of transition in the world marred by sick religious philosophies. And Hindu identity and wisdom will/should ultimately melt down into global civilization which it has enriched with Vedas, Buddha, Nanak, Mahavir, Upanishad, Geeta and Ramayana.