f. Why does Hinduism have many Gods?

Hindus believe in one Supreme God who created the universe. It is an all-pervasive divine reality, formless (Brahman, nirgun), or manifested in different forms (Ishvara, God/Goddess or Deities; sagun). Contrary to prevailing misconceptions, Hindus worship One Supreme Being, though by different names. 

The Sanskrit hymn, Rig Veda I.164.46:

Ekam sat vipraha bahudha vadanti

Truth is one, the wise call it by many names.

The government may be contacted through the postal service, the police, the judiciary and the office of the President. We can distinguish between different aspects of the functioning of the government, while still agreeing that there is only ONE government. Hindus believe that the ONE divinity can be experienced in myriad ways. Even for one form of divinity, say Vishnu (the all-pervading one), Hindus routinely memorize 1,000 names for an essentially nameless and formless divinity. There is one Truth, and the wise know to call it by many names.

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Other reading material: HAF: Short answers to real questions about Hinduism

Hinduism Today: Why does Hinduism have so many Gods?Relevant videos: Swami Nikhil Anand Hinduism Q & A: How Many Gods Are There