There is a very beautiful story from the Hindu mythology's Mahabharata that provides an insight to the meaning of our existence.
Five brothers who were kings and their wife, the queen (this happened through a misunderstanding of the concept of 'sharing' as expressed by their mother) after a long reign were embarking on their final journey - to heaven. To do so they had to trek up a mountain and along the way they were joined by a dog. The climb was so arduous they began to die off. Even the second oldest brother, the 'hercules' of his era, fell.
However, the eldest, Yudhishthira and the dog made it to the top where they were greeted by Indra the king of the gods. He congratulated Yudhishthira and told him to get into his chariot to go to heaven, but the dog walked in first.
Indra was infuriated (he had this tendency): "I will not tolerate a dog in my chariot! Get him out and let's go."
Yudhishthira said, "Through my journey up the mountain, my queen and my brothers left me. Only this dog stayed with me - I cannot leave him now."
Indra exclaimed, "What! Are you mad? Dogs do not belong in heaven! Do you want to give up your place for a dog?"
Yudhishthira replied, "The dog stayed faithfully by me, I will not desert him - even for heaven."
Just then the dog transformed himself into Yama the god of the underworld and spoke: "You have chosen rightly, my son. In life all shall leave us, our passions, our acquaintances and even those we love dearest. Only our Dharma, like the dog, stays with us regardless. To this Dharma, we must be true."