North Brabant and Limburg have been historically the most Catholic parts of the Netherlands, and Catholicism and some of its traditions now form a cultural identity rather than a religious identity for people there. The vast majority of the Catholic population is now largely irreligious in practice (in line with the rest of the Dutch population). Research among self-identified Catholics in the Netherlands in 2007 showed that only 27% could be regarded as theist; 55% as ietsist, deist, or agnostic; and 17% as atheist. In 2015 only 13% of self-identified Dutch Catholics believe in the existence of heaven, 17% in a personal God and fewer than half believe that Jesus was the Son of God or sent by God.