In this article I examine public statements about the relationship between private faith and public reason through the pronouncements of four leading politicians: Tony Blair (United Kingdom), Helen Clark (New Zealand), Barack Obama (United States of America) and Kevin Rudd (Australia). Of the four, Blair and Rudd have been most articulate about the way in which their own personal faith-commitments have informed their political motivations, but in doing so both men have had to negotiate a broader cultural suspicion of 'doing God' in public. Whilst religion may be regarded as representing a strong 'moral compass' for a politician, those espousing a religious faith in public also have to contend with public anxieties about religious extremism. Of the other two, I argue that Obama speaks into a more receptive public arena, and that part of his skill has been to tap into a long-standing tradition in American public life which, despite separation of church and state, is more attuned to the casting of political values in religious language. Helen Clark is the only one of the four to identify herself as 'agnostic', yet her support for the 2007 Statement on Religious Diversity signals a new willingness on the part of a political culture that has tended to be 'functionally secular' to embrace the notion of religious faith as a part of healthy civil society. All four examples, therefore, furnish us with insights into different dimensions of the relationship between a politician's personal faith and their public accountability in contemporary western democracies.