24 This long discussion has, I believe, brought out the truth that no sound argument has ever been adduced in favour of a distinction between One Who is, and One Who is not, true God, in those passages where the Law speaks of God and God, of Lord and Lord. I have proved that these terms are inconsistent with difference between Them in name or in nature, and that we can use the name as a test of the nature, and the nature as a clue to the name. Thus I have shown that the character, the power, the attributes, the name of God are inherent in Him Whom the Law has called God.
I have shown also that the Law, gradually unfolding the Gospel mystery, reveals the Son as a Person by manifesting God as obedient, in the creation of the world, to the words of God, and in the formation of man making what is the joint image of God, and of God; and again, that in the judgment of the men of Sodom the Lord is Judge from the Lord; that, in the giving of blessings and ordaining of the mysteries of the Law, the Angel of God is God. Thus, in support of the saving confession of God as ever manifested in the Persons of Father and of Son, we have shown how the Law teaches the true Godhead by the use of the strict name of God; for, while the Law states clearly that They are Two, it casts no shadow of doubt upon the true Godhead of either.
Source: On the Trinity (New Advent)