Why Vishnu Keeps Coming Back
Every time the world is in real trouble, he shows up. Different form, same promise. He's come before. He'll come again.
Vishnu has come down to the world ten times so far. Each time, the world was in real trouble. Each time, he came in a different shape. A fish. A turtle. A boar. A half-lion. A small boy. A warrior with an axe. A prince. A cowherd. A teacher of kindness. And one more, who has not come yet, but who will. This is the story of all ten of his visits. Most of them, you already know.
A Promise Made Long Ago
A very long time ago, when the world was still young, Vishnu lay back on the great serpent Sheshanaga in the middle of the cosmic ocean. The serpent's hood made a soft canopy over his head. The ocean was calm. Stars were spinning slowly above.

Vishnu was thinking about the world he had just helped create.
He knew, even then, that the world would not always be calm. Some days the rains would not come, and the people would suffer. Some days a king would become a tyrant, and the kind people would have nowhere to go. Some days a demon would grow too powerful, and good families would have nowhere to hide. Some days a teacher would come along who twisted dharma, and the children would be confused.
He smiled gently. He made a promise, out loud, to the empty sky.
"Whenever the world is in real trouble, whenever dharma weakens and adharma rises, I will come down. I will not stay away. I will come in whatever shape the trouble needs. A fish if a flood is coming. A boar if the earth is sinking. A boy if a king has gone mad. A teacher if the children are lost. I will keep coming. As many times as it takes."
The Bhagavad Gita preserves the exact verse, in chapter four. Yada yada hi dharmasya glanir bhavati... Whenever dharma weakens and adharma rises, I myself come down.
And so he has. Nine times so far. With one more still to come.
A Roll-Call You Already Know
This is the last lesson of our entire course. So instead of telling you one new story, we are going to tick off, one by one, the ten times Vishnu has shown up. You already know most of them. We have been telling them to you all along.