There is an implicit theory of personality in Christian theology, but it has rarely been worked out in a way that is specifically theological. This exploratory attempt to formulate a theory of personality development and its relation to psychotherapy is grounded in clinical experience with both individual and group psychotherapy, and in theological and biblical study. From a theological perspective, the basic structure of this theory is rooted in the doctrine of the Holy Spirit. The basic psychological contribution comes from the existential movement in psy chology and psychotherapy.