 At the same time, while 23% of U.S. adults are religiously unaffiliated, only one member of Congress (Kyrsten Sinema, D-Arizona), or 0.2% of that body, claims no religious affiliation.In most European countries, however, religion has a much smaller influence on politics although it used to be much more important.For instance, same-sex marriage and abortion were illegal in many European countries until recently, following Christian (usually Catholic) doctrine.