18. It should be known that charity and faith make one, as the will and the understanding do, since charity has relation to the will and faith to the understanding. It should likewise be known that charity and faith make one, as affection and thought do, since affection has relation to the will and thought to the understanding; likewise that charity and faith make one as good and truth do, for good has relation to affection, which belongs to the will, and truth has relation to thought, which belongs to the understanding.
In a word, charity and faith make one, like essence and form, since the essence of faith is charity, and the form of charity is faith. Hence it is evident that faith without charity is like a form without an essence, which is not anything; and that charity without faith is like an essence without form, which likewise is not anything.