The devas were engaged in perpetual fight against the demons. Sometimes they won, sometimes they were defeated. This being a continuous process oil tug-of-war, the devas wanted to possess the nectar, so that they would become immortal.
They churned the Milky Ocean by placing Mount Meru as their churning staff. They used the snake Vasuki as the rope to churn with. The head of the snake was held by the devas and the tail by the demons.
Author : Shri R. K. Das