There are so many gods in Hinduism. Do Hindus believe that there are multiple Gods ? Why do they worship multiple gods ?
There are 33 devas (divines) that include Agni, Indra, Varuna, Vayu and others. There are many references to these names in the vedas. If we analyze it we could see that each one is an essential function (fire, water, air, sun etc) that supports our living in this world. So these 33 aspects are hailed in the vedas. But Hindus consider the trinity (Lord Brahma, Lord Vishnu, Lord Shiva) to be above these divines. While brahma does not get worshipped by many as the God, shiva (rudra is an aspect of Lord Shiva) and vishnu are worshipped by the Shaivites and the Vaishanavaites respectively. Along with Shaivism and Vaishnavism, shaktam, ganapatyam, kaumaram, sauram are the four religions that make up the shanmata (six religions) on the Hinduism.
Hindu scriptures state clearly that there is only one Supreme God (ekam sad viprah bahuta vadanti). Then why are so many deities and worship ? It can be understood by reading the scriptures that each of these devas represent/have an aspect/energy of the Supreme. So in essence it is a complete divine system that operates. For example the Shaivites consider shakti as the dynamic part of the Supreme. Each of the six religions of Hinduism would call by different names and would put forward different philosophies, but all agree that there is one and only one Supreme God.
It is in fact the specialty of Hinduism that it lets multiple perspectives of the God to coexist on its platform, all sharing the same common dharma.
In essence there is only one God and the other divines (many times callas as gods) are responsible of one part of nature or other. The God is worshipped in multiple perspectives, names in Hinduism that has six major religions in it. This has been possible due to the tolerance of Hinduism.
The different practices based on the three Vedas, Samkhya, Yoga, Pashupata, Vaishnava etc. say this is superior, that is superior etc. But as the sea is the final resting place for all types of streams, You (God) are the final reaching place for all those paths. – shiva mahimna stotram