242. 2. Their first son, Cain, killed his brother Abel, and God did not dissuade him by talking with him beforehand, but simply cursed him after the fact. Since Adam and his wife mean the earliest church, as just noted [241], Cain and Abel as their first sons mean the two essential qualities of that church, love and wisdom, or charity and faith. Abel means love and charity, and Cain means wisdom or faith, particularly wisdom separated from love or faith separated from charity. When faith has been separated, wisdom tends not only to reject love and charity but to destroy them, killing its own brother.

It is reasonably well known in Christian circles that this is what faith does when it is separated from charity--see Teachings for the New Jerusalem on Faith.

[2] The curse of Cain is about the spiritual state that people who separate faith from charity, or wisdom from love, arrive at after death. However, in order to prevent the death of wisdom or faith, a mark is placed on Cain so that no one will kill him [Genesis 4:15]. This is because love cannot exist without wisdom, or charity without faith.

Since the meaning of this is very much like the meaning of eating from the tree of knowledge, it follows right after the description of Adam and his wife. People who have separated faith from charity are wrapped up in their own intelligence; while people who have faith because of their caring have a gift of intelligence from the Lord and are in sympathy with divine providence.