Religiosity and spirituality (R/S) may positively interfere with various dimensions of human existence and are an integral part of many people’s lives. However, this interference may also be negative in some aspects, e.g., regarding mental and physical health or behavioural outcomes. More research is needed to better understand this negative interference and the associations of R/S with health outcomes and the pathways contributing to these links. Therefore, this thesis aimed to assess the associations of R/S, negative religious coping (NRC) and religious conspiracy theories (RCT) with insecure attachment in childhood and adulthood, as well as the potential impact of R/S on mental health and vaccination attitudes during the Covid-19 pandemi...