20. For whosoever doeth what is evil. The meaning is, that the light is hateful to them for no other reason than because they are wicked and desire to conceal their sins, as far as lies in their power. Hence it follows that, by rejecting the remedy, they may be said purposely to cherish the ground of their condemnation. We are greatly mistaken, therefore, if we suppose that they who are enraged against the Gospel are actuated by godly zeal, when, on the contrary, they abhor and shun the light, that they may more freely flatter themselves in darkness