Dr. John Rao speaks of the way in which the Gregorian pilgrimage to God involved a deeper understanding of how the Incarnation required the transformation of all things in Christ. It is understandable that heresies which detested the idea of the Incarnation and its meaning for the world would resist. Manichean beliefs in the evil of Creation reared their head by the 1100's and 1200's. Taken from: Christianity in the High Middle Ages - 1995 VonHildebrand Institute