The whole thrust of the Buddha’s teaching is to master the mind. If you master the mind, you will have mastery over body and speech, and your own and others’ suffering can only come to an end. But if you leave the mind full of negative emotions, then however perfect the actions of your body and the words you speak might seem, you are far from the path. Mastery of the mind is achieved through constant awareness of all your thoughts and actions. Check your mind over and over again, and as soon as negative thoughts arise, remedy them with the appropriate antidotes. When positive thoughts arise, reinforce them by dedicating the merit they bring, wishing that all sentient beings be established in ultimate enlightenment.
– Dilgo Khyentse Rinpoche
from the book “The Heart Treasure of the Enlightened Ones”