Is Hinduism polytheist or monotheist?

People often ask- there are so many Gods in Hinduism (360 million as per scriptures), then how do Hindus say that they believe in One God. The answer to this question depends on how you define God.

The truth of the matter is the moment you try to define God, it becomes something limited. Even though one should not try to limit God with one definition or one name, but one can always try to describe God with its attributes. Self-realized Saints, Rishis, Munis and sages of India have tried to ascribe many different attributes of God like omnipresence (present everywhere), eternal (never born and never dies), omniscience (infinite knowledge), omnipotence (unlimited power), Supreme Consciousness, complete and blissful.

Sanatan Dharma has been in existence since the beginning of mankind, before the arrival of Avatars like Sri Rama, Sri Krishna and others. Over thousands of years, it has become like a huge umbrella covering wide aspects of the spirituality and divinity. This is the reason, Sanatan Dharma (Hindu Dharma) can be defined as polytheist, monotheist, nontheist, transtheist  or atheist, depending on one's definition of God.

Different aspects of the definition of belief systems evolved over the years. In the beginning, when people were Saatvic (pure) in nature, God was prayed as transcendent, immanent and omnipresent Sat-Chit-Ananda Parmatma (Eternal-Conscious-Blissful Supreme Soul). In those days, the knowledge of Vedas describing the Nirguna Nirakaar Parmatma used to propagate from one generation to next only by Shruti (verbally). There was easy access to Self-realized Rishis, Munis and Sages.

Then over the year, people became more Rajasi (Materialistic). For their impure intellect, it became difficult to grasp the concept of formless Nirgun Nirakaar Parmatma. To help the people understand the concept of God, Sages of Sanatan Dharma began to make it easier for people to grasp by means of telling the stories of Avatars of God. They gave a personal form to the omnipresent formless God for the benefit of people. Slowly people began to pray God with a personal form in different manners giving rise to the polytheist aspect of Sanatan Dharma. During the course of time, whenever the extremists tried to limit the limitless religion (Hinduism) with their own rules or systems (like caste-system), many different sects or religions came into existence from same Sanatan Dharma like Buddhism, Jainism, Sikhism etc.

Sanatan Dharma provides a complete package to the true aspirant of Truth. Guru-Shishya parampara (the tradition of master- disciple) is unique aspect of Sanatan Dharma which helps the true seeker to realize the omnipresent God within with the help of a Self-realized Master. As the seeker takes a deep dive into divine spiritual wisdom with the help of a Master and the holy scriptures, the seeker begins to appreciate the wholesome divinity and the magnificence of all the definitions of God. Since God cannot be limited by definitions, the path leading to God can also be in innumerable – in form of different sects, religions and theisms.   

It is wonderful to see how beautifully people of India have embraced different definitions of God in so many small sects and belief systems without any conflict. It is as beautiful as a magnificent garden having wide variety of colorful flowers.