One of the most important Hindu Epic is mahabharata. It can be taken as being opposite of the other epic, Ramayana. In Ramayana, the brothers are united and they fight a demon. In Mahabharata, the cousin brothers are not united. In fact, they hate each other so much so that the gauravas get destroyed by the pandavas in one mighty war.
It has many lessons for us. Why it is wrong for us to be jealous of others; why it is wrong to hate each other; why it is important to care for others and so on and so forth are explained beautifully through stories.