What is the core idea of Wang Yangming's theory of mind? What's the significance to reality?

The core idea of Wang Yangming's theory of mind can be summed up in a poem: "There is no body of good and evil, there are actions of good and evil, knowing good and evil is conscience, and getting rid of evil is character." His psychology is instructive to our reality, but only by combining his life story can we know what it is, and only by studying hard and practicing hard for ten years can we have a small success.