If we look at the nature of worldly views and activities, we find that they are caused by a lack of proper investigation. We operate under the illusion that the relative truth is something solid and truly existent, but this is the definition of delusion. If we look carefully, we find that the world is like a rainbow: vivid and colourful, but without any solid existence.

When a magician creates the illusion of horses, oxen, chariots, and so forth, although they [appear and] can move, they are actually nonexistent. In the same way, a person who has realised the emptiness of all phenomena recognises the activities of the world as an illusion. Nowadays, this is a very difficult thing to do - delusion is heaped on delusion and it spreads like monkeys imitating each other. We are so deceived that it is hard to find a way out. Having lost sight of the true nature of things, it is easy to waste one's life.

-- Dilgo Khyentse Rinpoche