Gandhi...

Happiness is when what you think, what you say, and what you do are in harmony.

If we could change ourselves, the tendencies in the world would also change.
As a man changes his own nature, so does the attitude of the world change towards him.
We need not wait to see what others do.

You must not lose faith in humanity.
Humanity is like an ocean;
if a few drops of the ocean are dirty, the ocean does not become dirty.