Meditation brings wisdom; lack of meditation leaves ignorance. Know well what leads you forward and what holds you back, and choose the path that leads to wisdom.
The method of trying to conquer hatred through hatred never succeeds in overcoming hatred. But, the method of overcoming hatred through non-hatred is eternally effective. That is why that method is described as eternal wisdom.
In what is seen, there should be just the seen; In what is heard, there should be just the heard; In what is sensed, there should be just the sensed; In what is thought, there should be just the thought. He should not kill a living being, nor cause it to be killed, nor should he incite another to kill. Do not injure any being, either strong or weak in the world.
Peace comes from within. Do not seek it without. It can be argued that peace and happiness comes from the subjective internalised perspective of realizing things could be worse and being grateful they aren't. The alternative view that peace and happiness comes from the objective external perspective of having more and better things than at present, while important for growth, can be a never-ending source of jealousy, dissatisfaction and disappointment. A balance of the two, where people are grateful for what they have while striving for more seems the best blended perspective.
Whatsoever, after due examination and analysis, you find to be kind, conducive to the good, the benefit, the welfare of all beings...that doctrine believe and cling to, and take it as your guide.