Answer by Chris Berlin:
Rather than being a “necessity,” the act of giving voluntarily in Buddhism is motivated by a recognition that all beings exist in interdependence. The interdependence of all things, combined with an awareness of those less fortunate, inspires compassion. Practicing selflessness in this way is thought to increase one’s own merit and is also an antidote to greed or grasping to possessions or other resources. Giving is an expression of the natural qualities of kindness and compassion.
Recognition of the interdependence of life also means taking care of the environment by keeping it pure and unspoiled, as well as attending to animals and also to spirits in some traditions by offering prayers, rituals, ceremonies, or other acts dedicated to the well-being of all life.
Traditionally, Buddhist lay people have long practiced the giving of alms, food, medicine, and clothing to monks and to monasteries in exchange for teachings and merit. This relationship is seen to be a sacred mutual dependence, and merit is shared on both sides for the benefit of all.
As a spiritual practice, generosity is the first of six “perfections,” or virtuous qualities, one cultivates for spiritual awakening. As such, one offers both material donations as well as the giving of spiritual resources out of kindness and compassion for the benefit and enlightenment of others.
In addition to giving to the poor, generosity also includes sharing one’s spaciousness of heart, such as sharing in the loss of a loved one or family member, offering a practice of loving-kindness through meditation, or being present with someone within their suffering.
Buddhists often quote the Buddha from an early scripture: “What is the accomplishment in generosity? A noble disciple dwells at home, with a heart free from the stain of stinginess, open-handed, pure-handed, delighting in relinquishment, one devoted to charity, one who delights in sharing and giving. This is called accomplishment in generosity