And they celebrate in so many different ways.
These festivals seem to reflect the character of the belief system, having originated when the religion was young.
Caption for the image in OP:
Hindu FestivalsDevotees carry an idol of Hindu elephant god Ganesh, the deity of prosperity, into the water from Girgaum Chowpatty beach before immersing it in the waters of the Arabian Sea on the last day of the Ganesh Chaturthi festival in Mumbai, on September 11, 2011. Idols are taken through the streets in a procession accompanied by dancing and singing, to be immersed in a river or the sea symbolizing a ritual send-off of his journey towards his abode in "Kailash", while taking away with him the misfortunes of all mankind. (Reuters/Vivek Prakash)
A Hindu devotee smokes marijuana after taking part in a "Bol Bom" pilgrimage in Kathmandu, on July 25, 2011. The faithful, chanting the name of Lord Shiva, run some 15 km (9 miles) barefoot to Pashupatinath temple seeking good health, wealth and happiness. (Reuters/Navesh Chitrakar)
Hindu Festivals