the principle of mixed styles makes its way into the writings of the Fathers from the Judaeo-Christian tradition. The true heart of the Christian doctrine — Incarnation and Passion — was totally incompatible with the principle of the separation of styles.
Auerbach argues that biblical style is constitutively defined by the mixing of high and low registers, a formal necessity dictated by the doctrine of Incarnation itself.
, Mimesis: The Representation of Reality in Western Literature, 1953thesis