Now you are asking the important question. Its really difficult to answer who's the actual GOD, what he would look like... Just imagine our universe as a ball floating inside a vast sea, can we even imagine how vast the sea is as long as we are inside that ball. The Gods we know (if exists) must have been created to control and continue this earth. There will be thousands of these worlds, where people will have different kind of body, different beliefs and may be different God. Can you believe that in that world people would be worshipping same Gods Rama and Krishna? No, because Rama and Krishna never took birth in that world. Then whos Vishnu, Shiv, the Gods we believe on. It%u2019s just like a post or designation (like PM of India), its not the actual entity. They have been assigned to do certain job for this world (that we know). Its means they have to die just like us. Our life is only 100 yrs and may be they would live for trillions of yrs. If you go through the "Kalyan", they have defined the age of Brahma, Vishnu, Shiva.. But as nobody knows whos the ULTIMATE God, that%u2019s why they treat somebody (Krishna, Vishnu...) as GOD whos immortal. Let me tell you one beautiful story. Once there was a queen and she was worried that her husband would leave her after his death. So she prayed to God and she said she don't want to be separated from her husband so he should never leave the room even if he dies. God said ok. After sometime, her husband died. So she called the God