Athanasius also wrote a two-part Against the Heathen and The Incarnation of the Word of God. Completed probably early in his life, before the Arian controversy, they constitute the first classic work of developed Orthodox theology. In the first part, Athanasius attacks several pagan practices and beliefs. The second part presents teachings on the redemption. Also in these books, Athanasius put forward the belief that the Son of God, the eternal Word through whom God created the world, entered that world in human form to lead men back into the harmony from which they had earlier fallen away.