This article shows, as Peter Berger's desecularisation theory indicates, that the contemporary world is mainly religious as much as it was in the past, and although pluralisation somewhat loosens religious beliefs, people are largely religious. On a probability sample of a national survey in Iran, we show that Iranian's people are mainly religious. However, they are not very comment to religious behaviours, especially in treatment with others and the affairs of everyday life. Also, education has a negative, but minor impact on individuals' religiousness. However, it exerts a more impact on other dimensions of religious life, religious tolerance, and secularisation of individuals.