Holy day of obligation.

What on earth do we celebrate on April 22? No, it's not the Resurrection, but that's a good guess, since Easter is just six days beforehand. This feast was celebrated for the first time just 36 years ago, and, unlike so many holy days that recall either a person or an event, this day celebrates a place--the planet Earth.

Earth Day, neither created nor proclaimed by any church, has become a sacred day for many, so much so that church groups now appreciate its deeply spiritual nature (or have at least realized that environmental concerns are an effective hook for evangelization). One group, the Evangelical Climate Initiative, even has a website: www.christiansandclimate.org.

Long before Earth Day and the Evangelical Climate Initiative, one voice for care of the earth as sacred imperative could be heard, had anyone listened. It was Thomas Berry, a Passionist priest still passionate about the natural world as both gift and sacred trust to humanity. Throughout his long and distinguished career, Berry has devoted his life to exploring theologically how individual behavior, institutional policies, and cultural mores either advance or impede the life of the planet.

Berry believes that the natural world is more than the stage for humanity to strut its stuff. Rather, the natural world is the primary context for theology. Earth is the major source of revelation that moves humanity toward a faithful transformation of consciousness and behavior. To ignore, impede, or annihilate any part of the natural world destroys the divine message of creation and cuts humanity off from salvation.

The many and varied celebrations of Earth Day, often good at consciousness raising, are but dim reflections of the theological vision of Thomas Berry. Planting trees, cleaning rivers, recycling waste, all are in themselves good works but limited when compared with the greater theological reality so profoundly articulated by Berry.

Come Earth Day, participate in some of these activities for sure. After Earth Day, read Thomas Berry's book The Great Work (Harmony/Bell Tower). It will be one of your great works.

PETER GILMOUR ([e-mail]) teaches at the Institute of Pastoral Studies of Loyola University Chicago.