Hindu Dharma is a comprehensive collection of philosophies in which the concept of Divinity ranges from a negation of the existence of the Divine, to agnosticism, to firm conviction in the existence of a single, all pervasive, independent, immanent and transcendent Divinity called “brahman“.
Hindu Dharma is an harmonious blend of various traditions called “sampradayas”, each sampradayas have a set of philosophical tenets called “darshanas”, these various philosophical traditions profess their own idea of divine, example: certain thinkers of sankhya tradition negate the necessity of god, and profess that the universe (prakriti) is governed by actions (karma) of purusha/people and their consequences, where as Advaita professes the idea that everyone is Brahman. Hence, some traditions negate the existence of the divine, some view it as just an observer, and some view it as a prime driver of all things living and non-living.
Bhagavad Gita, one of the primary texts of Hindu Dharma has a verse, suggesting that the human mind finds it extremely difficult to fixate its mind on something that is abstract and without form (termed avyakta, or unmanifest). Hence, thinkers, scholars and great rishis in Hindu civilization have often guided us by providing various forms of divinity, that we can fixate our mind on for our contemplation or meditation. Each of these also symbolizes an idea, example: In various avatars of Vishnu, the angry form of Narasimha or Parashurama is for destruction of evil, whereas the calmer forms of Vamana, Krishna and Buddha are for spreading knowledge.
