As the French (and Canadian) debate is still quite polarized by "laïcité" (laicity) and the challenge of public regulation of religion, let's have a wider look and remind (among others) the works of Jean-Paul Willaime (link to his page).
A worldwide leading sociologist of religion, Director of studies at the École Pratique des Hautes Études (EPHE, Religious Studies section) and former president of the International Society for the Sociology of Religion (ISSR), visiting professor at the College of Europe, Dr Jean-Paul Willaime is always worth being read.
He has authored many articles in English, including "European Integration, Laïcité and Religion" (link).