In January 2011 Lettini organized in Rome an international interdisciplinary course on ecumenical theology. Bringing together all her institutional affiliations, she made the course a collaborative project of Waldensian Theological Seminary, Starr King School for the Ministry, Union Theological Seminary in New York, Union Presbyterian Seminary, and the American Waldensian Society. In a 2017 interview Lettini said she would like it if academic theology could develop more organically as community theology, with real dialogue between the believers and theologians; she thinks the current rapprochement between Protestants and Catholics is a good thing, but, pointing to the history of Christian complicity in the world's worst atrocities, she considers their differing theological tenets less important than "to offer a corrective to these aberrations of the Christian faith."
