Paul O’Callaghan is professor of Christian anthropology at the Pontifical University of the Holy Cross in Rome and fellow of the Pontifical Academy of Theology. He is the author of The Christological Assimilation of the Apocalypse (2004) and Christ Our Hope: An Introduction to Eschatology (2011), as well as other books and numerous articles in six languages that have been published worldwide. He has also been a participant in the Lutheran-Catholic dialogue on justification, published the book Fides Christi: The Justification Debate (1997), and was involved in the preparation of the 1999 declaration on justification.