Orlando Costas, in his brief life, was one of the most influential Latin-American theologians of the 20^th century. He filled multiple roles in the Latin American Mission in Costa Rica from 1970-76, at which time he authored eight different books on topics such as homiletics, evangelism, church grown, and church history. In 1976 he completed his ThD at the Free University in Amsterdam, writing his dissertation on the topic Theology of the Crossroads in Contemporary Latin America: Missiology in Mainline Protestantism, 1969-1974 under the mentorship of Johannes Verkuyl.

He served as a missionary with the Board of World Missions of the United Church of Christ from 1977-80. Through the Latin American Center for Pastoral Studies, he helped found and edit the periodicals Pastoralia and Occasional Essays.

In 1980 Orlando accepted the position as Professor of Missiology and Director of Hispanic Studies and Ministries at Eastern Baptist Theological Seminary. In 1984 he became the academic dean of Andover Newton Theological School. He was a leader in the Latin American Theological Fellowship and the Lausanne movement. Along with several other Latin American theologians and missiologists, he was an advocate of holistic mission.

Among his best-known books are The Integrity of Mission: The Inner life and Outreach of the Church (1979), Christ Outside the Gate: Mission Beyond Christendom (1982), and Liberating News: A Theology of Contextual Evangelization (1989).

Dr. Costas died in 1987 at the age of 45.