Following the German sociologists of religion Kaufmann and Gabriel, I try to understand the evolution of and functioning of religions in the last centuries as their being involved in complex processes of religious modernization. After developing an historical-sociological long-term view on religious modernization, resulting in the book 'The Age of World Religions' (published in Dutch in 2007 and in German in 2010), the paradigmatic framework is now being used to analyze the evolution of the Catholic Church in Western modernity, from the French Revolution till the 21st century, yet with an emphasis on contemporary developments (see e.g. Hellemans & Jonkers (Eds.), 'Envisioning Futures for the Catholic Church', 2018). The basic idea reads: consider religion (and thus also Catholicism) as part and parcel of modernity and not as its opposite.