Thich Nhat Hanh in The Path of Emancipation: Talks From a 21-Day Mindfulness Retreat,

There is affliction and suffering within us. Our suffering represents both our individual suffering and the suffering of our ancestors, parents, and society. Every time we practice mindful breathing and take good care of our bodies and feelings, we relieve our suffering. We get the benefit of the transformation and healing, and our ancestors and society also get the benefit. Any smile that we produce will affect society. We can touch society within ourselves. Any step we take in mindfulness that brings a little more solidity, freedom, and joy, also benefits society and our ancestors. Do not think that what you do to yourself does not affect the rest of society and the world. Peace and freedom always begin with our own practice. We know that the one contains the all. The emancipation of the individual is also the emancipation of society, of the collective element in us. The victory of Siddhartha at the foot of the Bodhi Tree was not for one individual alone. It was for the peace, joy, and emancipation of many, many living beings. If transformation takes place in us, at the same time, it takes place in the world. Even if you don’t see it, a transformation has taken place. If peace is in you, peace becomes possible everywhere in the cosmos. When you have peace inside, you look at the world, and it is different. I think many of us have had this experience.