James W. Fowler "Stages of Faith"
Fowler's research and theories are similar to the work of two famous psychologists. Jean Piaget was famous for his cognitive development theories while Kohlberg is known for his work in moral reasoning. Fowler's theory of spiritual development stretches from infancy to old age. Although not an age- related stage theory, Fowler believes that all people go through stages of spirituality during their lives. Click on a stage to the right for an explanation.

More info on Dr. Fowler at Emory University ETHICS | THEOLOGY

I think that Fowler's stage theory is a great way to look at things. However, even he admits that faith development is hard to pin down into clear stages. It is hard enough to define words like faith and spirituality. One thing is certain, most people wonder about what is out there beyond what we know through science and reason.

For more info on Fowler and others, check out the theories page.