Question

Why does Hinduism present thousands of forms of the same god?

Answer 1

The reason why Hinduism presented thousands of forms of the same god is because followers were able to better relate to Brahma.

MAIN HINDU GODS:
Brahma - The Creator
Vishnu - The Preserver
Shiva - The Destroyer/Transformer
Saraswati - Goddess of Knowledge/Music/Arts
Lakshmi - Goddess of Wealth/Prosperity
Parvati - The Divine Mother

OTHER GODS:
Ganesh - God of the Intellect and the remover of obstacles
Durga - A fiercer form of Parvati
Rama - The 7th avatar (incarnation) of Vishnu
Hanuman - An ape-like god known for assisting Rama 
Surya - God of the Sun
Krishna - The 8th avatar (incarnation) of Vishnu
Kali - Goddess of time and death
Murugan - God of War

 
Each of the Gods represent one aspect of Brahman.