Gregory the Great

Or shall it please Him, from Whom nothing can be concealed? Or like as a man will He be deceived by your deceits.

Heretics shew God deceit in that they fabricate such things as cannot be pleasing to the very Being, in Whose behalf they say them. And whilst they set themselves as if to defend, they only offend Him, in that they are brought to the ground in fighting against Him, Whom they appear by preaching to be serving. Hence it is said by the Psalmist, That Thou mightest still the enemy and the defender. For every heretic is to Almighty God an 'enemy and defender,' for wherein he strives in his way to defend Him, therein he fights against His truth. But because nothing can escape God's sight, He judges according to that in them, which they think within their heart, but not by their appearing without to be doing Him service.