The friendship between Abraham Joshua Heschel and Reinhold Niebuhr was both personal and intellectual. Neighbours on the Upper West Side of New York City, they walked together in Riverside park and shared personal concerns in private letters; Niebuhr asked Heschel to deliver the eulogy at his funeral. They were bound by shared religious sensibilities as well, including their love of the Hebrew Bible, the irony they saw in American history and in the writings of the Hebrew prophets, and in their commitment to social justice as a duty to God. Heschel arrived in the public sphere later, as a public intellectual with a prophetic voice, much as Niebuhr had been for many decades prior. Niebuhr’s affirmation of the affinities between his and Heschel’s theological scholarship pays tribute to an extraordinary friendship of Protestant and Jew.