435. XII. The first thing in charity is to banish evils, the second is to do good deeds which may be of use to the neighbour.
The leading role in the doctrine of charity is played by this statement, that the first thing is not to do evil to the neighbour, the second is to do good to him. This dogma forms as it were a gateway leading to the doctrine of charity, It is well known that from birth everyone has evil lodged in his will; and because every evil is aimed at people both near and far, as well as one's community and country, it follows that hereditary evil is evil directed against the neighbour of whatever degree. Reason itself can show anyone that in so far as the evil lodged in the will is not removed, so far is the good he does impregnated with that evil. For in that case the evil is inside the good, like a kernel in a nut-shell or marrow in a bone. Although therefore the good done by such a person looks like good, it is not intrinsically good. For it is like a glistening shell within which the kernel is eaten away by maggots; and like a white almond which is rotten inside, so that rotting passages extend to the surface.
 Willing evil and doing good are essentially two opposites. For evil is the product of hatred directed against the neighbour, good that of love towards the neighbour; or if you like, evil is the neighbour's enemy, good is his friend. These two cannot both exist in one mind, that is, the evil in the internal man, the good in the external man; if it does, the good in the external is like a wound treated with palliatives, but containing rotten pus inside it. A person then resembles a tree with a worn-out root, yet producing fruit which outwardly seems to be tasty and fit to use, but inwardly is bitter and useless. Such people are also like dross thrown away, which when superficially polished and given pretty colouring is put up for sale as precious stones. In short, they are like owl's eggs passed off as those of a dove.
 People should know that the good a person does in his body comes from his spirit, that is, the internal man. (The internal man is the spirit which lives on after death.) Consequently when such a person puts off the body, which made up his external man, then he is totally and utterly in the grip of evils, and takes pleasure in them, eschewing good as attacking his life.
 The Lord teaches in many passages that a person cannot do good which is essentially good until evil has been removed:
They do not gather the grape from thorns, nor figs from thistles; a rotten tree cannot produce good fruit, Matthew 7:16-18.
Woe to you, scribes and Pharisees; you clean the outside of the cup and dish, but the insides are full of robbery and intemperance. You blind Pharisee, clean first the inside of the cup and dish, so that the outside too may be clean, Matthew 23:25-26.
And in Isaiah:
Wash yourselves, remove the wickedness of your deeds; cease to do evil, learn to do good, seek judgment. Then if your sins were as scarlet, they will become white as snow, if they were red like purple, they shall be like wool, Isaiah 1:16-18.