58. In matters of theology, concerning everything whatever, the idea is formed according to each person's understanding; and this is the case, also, with those things of which it is said that the understanding must be kept under obedience to faith; such things, especially, are those which are from the Creed of Athanasius respecting the three Persons. The idea which is formed concerning a thing, is the understanding of it; if there be no understanding of it, there is merely a knowing, and they are but empty words which are thought of. The idea is manifest in the other life. Such ideas as are formed by man respecting the Trinity, and concerning the union of the Divine and the Human in the Lord, are many, and they are such as rather destroy than build up; I am not willing to recount them, because they are for the most part full of incongruities; when nevertheless the thought of God as being one, and that one the Lord, is the principal and fundamental in all things in the doctrine of the church; without that, no one can be saved.