4997. 'How then shall I do this great evil, and sin against God?' means that, this being so, they exist set apart and not joined together. This is clear from the meaning of 'evil' and likewise of 'sin' as a state when things are set apart and not joined together. That is to say, it describes what happens if spiritual natural good is joined to unspiritual natural truth; being unlike and incompatible the two pull away from each other. The expressions 'doing evil' and 'sinning against God' are used because regarded in itself evil, and sin too, is nothing else than being parted from good. Also, evil exists essentially in disunion, as is evident from what good is. Essentially good is a joining together because all good stems from love to the Lord and love towards the neighbour. The good of love to the Lord joins a person to the Lord and consequently to all good that goes forth from the Lord; and the good of love towards the neighbour joins him to heaven and the communities there, so that by means of this love as well he is joined to the Lord. For properly speaking, heaven is the Lord since He is the All in all there.
[2] But with evil the opposite applies. Evil stems from self-love and love of the world. Evil stemming from self-love sets a person apart not only from the Lord but also from heaven, for he loves no one but himself and others only insofar as he sees them as part of his self-interest, or as they identify themselves with him. Consequently he turns everyone's attention towards himself and entirely away from others, most of all away from the Lord. When a large number act like this within a single community it follows that all are set apart from one another; inwardly each sees another as his enemy. If anyone acts contrary to his self-interest he hates that person and takes delight in his destruction. The evil of the love of the world is not dissimilar, for this consists in a longing for other people's wealth and goods, and in a longing to gain possession of everything owned by others; and these longings too lead to all kinds of enmity and hatred, though in a lesser degree. For anyone to come to know what evil is, and so what sin is, let him merely try to see what self-love and love of the world are; and to come to know what good is, let him merely try to see what love to God and love towards the neighbour are. By trying to do this he will come to see what evil is, and as a consequence what falsity is; and from this he will come to see what good is, and as a consequence what truth is.