Differences between Protestants and Catholics in religious beliefs and behavior are revisited in the light of growing theoretical and empirical evidence for stages of secularization and a remaining religious core in Western societies. To what extent are remaining Protestants more religious than before and compared with remaining Catholics? Analyzing repeated cross-sectional survey data from 1985 to 2012 in the US, Canada, and Great Britain, we find that, in most cases, Protestant affiliation has declined more significantly than Catholic affiliation. Yet, individuals who declare themselves as belonging to a Protestant denomination have higher rates of regular service attendance, prayer, and Christian beliefs than those previously. They have also surpassed these same rates among Catholics in both the US and Canada and are on track to do so in Britain in the coming years.