“Nibbana is not a location or condition somewhere outside of us. Rather, it is within. Nibbana is the total destruction of all defilements. The very moment our greed, hatred and ignorance are destroyed, nibbana arises. The key to overcoming defilements and reaching nibbana is cultivating (or training) the mind. As the Buddha said, “As rain does not get into a well thatched house, so craving does not get into a well trained mind.”
So how should we proceed? First, we must understand what we are trying to accomplish and develop some skill in mindfulness both during meditation and in life. We use this mindfulness to prevent external defilements from entering the mind by carefully guarding the senses. We also use it to prevent latent tendencies that exist as traces within the mind, such as craving, hatred, greed, jealousy and pride, from arising. If, in spite of these efforts, latent tendencies do arise or reach the stage of manifestation in words and deeds, we apply additional mindful efforts to overcome them.
Then, instead of worrying over past unwholesome thoughts, we arouse wholesome thoughts, such as generosity, patience, and loving-friendliness and use effort to strengthen the wholesome thoughts. In addition we use mindfulness to guard the senses against external sensory experiences that might stimulate any unwholesome tendencies. As we have said, mindfulness is in essence vipassana or insight meditation. Only insight meditation can train the mind to watch and discipline itself in order to purify it, eventually destroying all the defilements, including their latent tendencies.”
~ Bhante Gunaratana
pp. 34-35, “Meditation on Perception: Ten Healing Practices to Cultivate Mindfulness”