He wrote numerous books on theology, ideology, faith, hermeneutics, and social justice, and was an outspoken critic of what he perceived as church callousness toward oppression and suffering.
Ia menulis banyak buku tentang teologi, ideologi, iman, hermeneutika, dan keadilan sosial, dan merupakan pengecam yang berani terhadap apa yang dipandangnya sebagai ketidakpedulian gereja terhadap penindasan dan penderitaan.