Traditionally, children have generally been considered as developmentally immature and unable to experience spirituality. However, more recent studies seem to indicate the opposite. This article aims to: (1) explore how religiosity and spirituality evolve in the developing person; (2) describe the perceptions of children about God; (3) explore how spirituality and religiosity are related to mental health; and (4) describe the relevant theories of faith development in children and adolescents and (5) make recommendations to foster spirituality and religiosity among children in order to promote healthier youth and a better society. The results of more recent studies show that children have an inborn spiritual nature and a craving to learn more about God or other spiritual themes, which seems to be a natural part of their development. Related studies analysed here show a synergistic positive association between spirituality and mental health. It seems spiritual development is an integral part of human development and cannot be studied in isolation, ignoring the other dimensions of one's being. Parents and educators need to take into consideration all aspects of human development including the spiritual one, and nurture children's spirituality as it can provide support and inner resilience at difficult times.