Why does God need incarnation?

There are people who don't believe in God, and don't see a God in themselves. He has to prove them wrong. That is why he incarnates.

How does he do this?
Because people who don't believe in God will question his existence, he has to prove his existence, and takes up a life form.

Why does he take up a life form?
Some will always exist who will say, "What does God have to bother? He neither suffers or dies."
To prove them wrong and help them see Him, he will have to show them that he can also suffer and die.

How does he prove that he can die too?
If one has to die, one has to take birth, and that is how he will incarnate. If one has to suffer, he must be sometimes happy too. That this temporary happiness is misconstrued as selfish service, is only a misconception, and it has to be uprooted.

That is why God will incarnate to show himself to people who don't believe in him.

Then what is the difference between incarnation and re-incarnation?
Even though he incarnates once and dies, there will be people, again and again, who still don't believe in him, because they are not the same people to whom he once proved his existence. So, will have to incarnate again and again, which is why he re-incarnates.

This is logical proof of the theory of re-incarnation in Hinduism.