Buddhist verse #42
Whatever an enemy may do to an enemy, or a hater to a hater, a wrongly directed mind will do greater harm. Neither a mother nor a father, nor any other relative will do so much; as a well-directed mind will do us greater service.
This verse so beautifully explains how dangerous the human mind can be. The mind is our greatest enemy and also our very best friend. When our mind is trained to be focused and attentive, it is gradually disciplined and one is able to achieve great heights. However, when we permit the mind to become lazy or if we allow our anger and other negative emotions to rule us, then the same mind can be a destructive force that causes far more harm than any external enemy.
It is for this reason that all Indian spiritual traditions highlight the importance of controlling the mind.