In the long war between the Devas and Asuras, each would occasionally conquer the world of the other, and then retake their home; appealing for help sometimes to Vishnu, sometimes to Shiva, sometimes to Brahma, sometimes to Shakti - and other non-beings - the opponents were restored to balance for a time as these non-beings took one form or another required for a temporary victory. Yet because of the fundamental nature of each opponent was so contrary to the other that they inevitably found themselves in conflict again: when they were victorious, they would forget their prior defeats and the help they had received; when they were defeated, they would forget their prior victories, and grow angry in their sulking.
When, once more, Vishnu was asked for help from the Devas after the Asuras had taken the Devaloka from them, and asked by the Asuras for help because the Devas had taken the Asuraloka from them, He understood the problem lay in this fundamental nature of things. What was required was for the asuras to willingly release what they took - but past experience suggested they would be utterly unwilling to do this. Yet, understanding the more fundamental nature of each individual being (even the Asuras) was toward an evolution of existence by several Ashrams, Vishnu instead devoted His effort to the growth and strengthening of the Asuras. Yet Vishnu found he was not Himself developed sufficiently, and devoted Himself toward personal growth.
The Devas were, reasonably, confused how any of this was helping their cause. Yet when, at last, Vishnu attained enlightenment, and began to teach Sannyasa, they saw the Asuras lay down all that they had taken up - even the Vedas themselves. Such a Vedasamnyasa was not atheism, and Vishnu could not teach contrary to the Vedas, being a manifestation of them. Such non-theism was the natural result of spiritual practice.
When the Devas retook their Devaloka, and the Asuras too returned home, it was not by conquest; there was nothing to enflame their pride and reignite the war. The Devas and the Asuras had taken up the Buddhist practices of Vishnu and outgrown their struggle; turning inward, they faced their true enemy, and changed their nature. Changing their own nature, they changed the nature of the world, and a new age began. In a sign of His growth, even King Indra personally attended to the Buddha, humbly, as any simple monk might, peacefully, side by side, with His former enemies. They had all given up everything - even their enmity.
Can you, too, give up your fighting, and relinquish both heaven and hell?