This is a movement originally conceived in 1988 on the Isle of Patmos, at a meeting of environmental and religious leaders. It was established out of concern for the water environment of the planet, which covers seven-tenths of the earth's surface. This concern is both theological and scientific, and one of the underlying purposes of the movement is to establish common ground on the implications and imperatives of this ecological crisis between representatives of faith communities, professional scientists, and environmental NGOs. The leading spirit of "Religion, Science and the Environment" is His All Holiness Bartholomew, Ecumenical Patriarch of the Christian Orthodox Church of Constantinople.

The organisation's mission is to raise awareness of pressing environmental issues and create a wider involvement in environmental matters by mobilising the world's religious leaders, scientists and environmentalists.

The movement operates through Symposium study voyages, with several hundred participants. Their aim is to debate the plight of the world's waters; to visit sites of special concern; to meet officials and NGO representatives in the countries visited; to propose solutions; and to initiate schemes or institutions for environmental co-operation and education.

Underlying RSE's methods is a core belief that the analytical tools of science and the spiritual messages of religion must work in harmony if the earth's environment is to be safeguarded against further degradation. Additionally, the RSE symposia have achieved significant outcomes for the regions, including: financial commitments from international institutions; greater regional co-operation among governments and non-governmental organisations; the establishment of the Halki Ecological Institute, an educational initiative to increase awareness and co-operation on environmental issues among the regional states; and environmental training for regional clergy, journalists, educators and youth.