God is One.
All the principles of human reason unite and as it were concentre in this, that there is one God, the Creator of the universe. A man who has reason, therefore, from a common attribute of his understanding, does not and cannot think otherwise. Say to any one of sound reason that there are two Creators of the universe, and you will find an aversion to you on account of it—and perhaps from the bare sound of the words in the ear. It is evident from this that all the principles of human reason unite and as it were concentre in the idea that God is one. There are two reasons why this is so. First, because the very faculty of thinking rationally, in itself considered, is not man's but is God's in him; upon that faculty human reason, as to the common attribute, depends; and this common attribute causes it to see this, as of itself. Second, because by means of that faculty man either is in the light of heaven, or derives thence the common principle of his thought; and the universal principle of the light of heaven is, that God is one. It is otherwise if by that faculty a man has perverted the lower principles of the understanding; he, it is true, has ability by that faculty, but through the intorsion of the lower principles, he turns it in another direction, whereby his reason becomes unsound. (D. L. W. n. 23.)
Who that has sound reason does not perceive that the Divine is not divisible, and that there is not a plurality of Infinite, Uncreate, Omnipotent beings,—and thus, Gods? If another, who has no reason, shall say that several Infinite, Uncreate, Omnipotent beings—therefore Gods,—are possible, if only they have one and the same essence; and that through this there is one Infinite, Uncreate, Omnipotent being and God:—Is not one and the same essence, the same one? and the same one cannot be several. If it shall be said that one is from the other:—Then he that is from the other is not God in himself; and yet God, from whom all things are, is God in Himself, (ib. n. 27.)
He who in faith acknowledges and in heart worships one God is in the communion of saints on earth, and in the communion of angels in the heavens. They are called communions, and are so, because they are in one God and one God is in them. They are also in conjunction with the whole angelic heaven, and I might venture to affirm with all and each of the angels there; for they all are as the children and descendants of one father whose minds, manners, and faces are resemblant, so that they mutually recognize each other. The angelic heaven is harmoniously arranged in societies, according to all the varieties of the love of good; which varieties all tend to one most universal