We are the only beings on Earth that can self-evolve, by using our conscience and mind to evaluate of our actions to find out where we are causing unhappiness. Then, we must engage our free will to choose to be better, and do the things that help us to grow spiritually out of the immature, selfish mammals we begin as, into the humanitarians that result from reaching our highest potential.
The most destructive lie we let our minds tell us is that this transformation is not possible, or is the figment of someone's imagination. The ego tells us this because the spiritual path entails the destruction of the negative ego. Under this existential threat, the ego defends itself like hell.