Gregory the Great

He will surely reprove you, if ye do secretly take His face. Presently when He ariseth He shall make you afraid; and His dread shall fall upon you.

This part, wherein He declares that 'the face of God is taken in secret,' may be understood in two ways. For there be some, who at one and the same time perceive truth in their hearts, and yet utter outwardly concerning God things that are false. For lest they should appear to be subdued, they both know the truth within, and yet assail it without. Hence it is well said in this place, He will surely reprove you, if ye do secretly take His face. As if it were expressed in plain words; 'Ye are the more to be blamed in His sight for falsehood, as ye see in yourselves what is true.' And there become, who when they turn back into the interior, contemplate the justice and righteousness of God, and in praying and weeping tremble with fear, but after the hour of contemplation has passed by, they return with as much boldness to their wickednesses, as if, being placed behind His back, they were not seen by the light of His righteousness. And so these with themselves in secret 'take God's face' as if it saw with a bodily sight, in that both, when they are present to Him, they flatter Him with their tears, and, when they are as it were gone from His sight, they make slight of Him by their practices. And these deserve to be beaten more for their evil doings, even in proportion as in the secret of their hearts they know the righteous judgments of God. And hence it is added; As soon as He stirreth up Himself, He will trouble you, and His dread shall fall upon you.

Seeing that Almighty God is of a nature unchangeable, in the wrath of judgment He is not capable of being moved; but by the expression proper to man, of God's being 'moved,' is understood nothing else than that enforcement of His rule of righteousness, by which the wickedness of man is chastised. Now righteous men conceive a dread of God before His indignation is stirred up against them; they fear Him at rest, lest they should feel Him as moved. But, on the other hand, the wicked then for the first time fear to be smitten, when they are under the rod, and terror then rouses them from the sleep of their insensibility, when vengeance is troubling them. And hence it is said by the Prophet, And only the vexing alone shall supply understanding to the hearing. For when they have begun to be stricken in vengeance for the contempt and neglect of God's precepts, then they understand the thing that they heard. And the Psalmist saith, When He slew them, then they sought Him. Therefore it is well said, As soon as He stirreth up Himself, He will trouble you, and His dread will fall upon you; in that the hearts of the children of perdition have not fear producing repose, but punishment producing fear.