Water Buffalo Theology marked the emergence of a self-conscious Asian Christian theology on the world scene when it was published in 1974. In this twenty-fifth anniversary edition, Koyama thoroughly updates the original, adding an retrospective introduction that records how he has changed his mind on many topics but maintained his position on others. In addition to eliminating several chapters, Koyama also adds one on his "pilgrimage in mission".

Water Buffalo Theology urges readers to abide by the first calling of Christianity -- to become an incarnation of God's love.