…once you have received the teachings, you have to take the medicine; you have to meditate and practice. If you understand the teachings but do not put them into practice through meditation, then you cannot gain direct realization. It is direct experiential realization that actually eliminates the mental afflictions. So if you do not actually take the medicine by practicing the teachings, how can you gain the ultimate cure — nirvana — the state which is beyond sorrow?
~ Geshe Lhundhup Sopa in Steps on the Path to Enlightenment, volume 1