This Data Guide provides the documentation of a national survey on religious and secular attitudes and behaviour in Dutch society 2005. The data files as well as additional documentation files of this publication can be downloaded from the online archiving system EASY of Data Archiving and Networked Services (DANS). DANS promotes sustained access to digital research data. For this purpose, DANS encourages scientific researchers to archive and reuse data in a sustained manner, e.g. by means of the online archiving system EASY. DANS also provides access, through NARCIS, to thousands of scientific datasets, e-publications and other research information in the Netherlands. In addition, the institute provides training and advice and performs research into sustained access to digital information. Driven by data, DANS ensures that access to digital research data keeps improving, by its services and by taking part in (international) projects and networks. Please visit www.dans.knaw.nl for more information and contact details. DANS is an institute of the Royal Netherlands Academy of Arts and Sciences (KNAW) and the Netherlands Organisation for Scientific Research (NWO).