Orthodox theology is intimately linked to spiritual experience. Thus it has a very different meaning to the present usage of " theology" coming from academia. The scientific methods developed in the West since the seventeenth century can be of benefit in many regards; however, strong roots in the Orthodox tradition are needed to avoid the risk of theology being "eaten up" by the human sciences. These roots are in the mystical tradition of the Church as passed down from the beginning and as expressed in the Holy Scripture, the Councils, the writings of the Fathers, the lives of saints, and its iconography; and as nourished in the liturgical life of the Church. This tradition " expresses the faith of the Church beyond time, the permanent faith of the Church, which is fundamentally the faith in Christ who ' is the same yesterday, today and forever' (Hebrews 13, 8)." The author presents a work that has both a theoretical and a practical scope, and is of relevance to all Christians.