To some extent, religious development rests on cognitive development or the development of thinking. Developmental psychologist David Elkind has explained this by showing that three key developments in children's thinking allow for key developments in their thinking about religion. Those three have to do with the ability to understand that objects and people do not cease to exist when they are out of sight (object permanence), the ability to not only represent or symbolize but understand what it means to symbolize, and the ability to give reasons and judgments using logic (i.e., conservation).
The first ability develops gradually during infancy. Around 3 or 4 years old it makes possible an appreciation for certain religious ideas, such as there are spiritual beings (e.g., God) that exist despite their not being visible and there is life after death. The second ability develops gradually during early childhood and makes possible school-age (around 6 or 7) children's appreciation for the many images and stories that define and make up their own religious tradition. The third ability develops gradually during late childhood and makes possible, around 11 or 12, an appreciation for different points of view about religion and religious issues. Developments associated with thinking, then, make possible the milestones in religious understanding and religious development.
Elkind also employs the familiar concrete-toabstract and global-to-specific dimensions to explain how particular religious concepts develop throughout childhood. The concepts of prayer and religious denomination provide prime examples. For young school-age children, the meaning of prayer is often concretely tied to speech while being simultaneously over-generalized to apply to animals as well as to humans. Only gradually, then, do children come to think of prayer abstractly and specifically as conversation by humans with God, its content usually including requests, confessions, or expressions of thanks. Similarly, the meaning of religious denominations begins with references to concrete characteristics such as whether someone goes to a church or a synagogue. Religious holidays are not always clearly distinguished from secular holidays, e.g., Valentine's Day. Only much later do children understand that differences between religious denominations have to do with abstract differences in beliefs and patterns of faith.
In sum, David Elkind's research and similar research in what is sometimes called the cognitivedevelopmental tradition shows clearly that religious development rests on cognitive development and that one important aspect of religious development has to do with the development of new meanings.