In many sutras the Buddha teaches lay practitioners to treat their parents, children, spouses, and colleagues with understanding and compassion. These sutras teach that each person has many roles in society and that each role dictates specific responsibilities and duties. Rather than putting blind faith in rituals and worship, the Buddha tells us that we should strive to mindfully undertake the responsibilities and duties of our normal lives. If everybody does so, the world will enjoy enduring peace. You can say that the Buddha was the first advocate of "engaged Buddhism."
Other sutras teach us to treat our parents, our country, our teachers, and all sentient beings with heartfelt gratitude for their generosity to us. If our parents do not need our help, we can show our gratitude by offering and dedicating ourselves to the benefit of our families, society, and all sentient beings.
Going one step further, the Mahayana tradition advocates the Bodhisattva Way, urging us to treat everyone as our parents, or as our good and virtuous friends who lead us to the Bodhisattva Way. Such friends help us in every possible way. Some help us in their positive influence. Others challenge our patience and equanimity through their negative influence, thereby indirectly making us improve our minds and actions. One who practices the Bodhisattva Way must show the utmost gratitude to everyone and vow to help them. In this sense it can be said that Buddhists have no enemies. Even when a person wants to hurt us, or succeeds in hurting us, we seek to influence him so that his harmful disposition will be limited in its effects. When there are no enemies, there are no wars.
Source : "A Pureland on Earth"