Works of St. Anselm, tr. by Sidney Norton Deane, [1903], at sacred-texts.com
This Essence itself is God, who alone is lord and ruler of all.
IT appears, then ‑‑ nay, it is unhesitatingly declared that what is called God is not nothing; and that to this supreme Essence the name God is properly given. For every one who says that a God exists, whether one or more than one, conceives of him only as of some substance which he believes to be above every nature that is not God, and that he is to be worshipped of men because of his preeminent majesty, and to be appeased for man’s own sake because of some imminent necessity.
But what should be so worshipped in accordance with its majesty, and what should be so appeased in behalf of any object, as the supremely good and supremely powerful Spirit, who is Lord of all and who rules all? For, as it is established that through the p. 142 supreme Good and its supremely wise omnipotence all things were created and live, it is most inconsistent to suppose that the Spirit himself does not rule the beings created by him, or that beings are governed by another less powerful or less good, or by no reason at all, but by the confused flow of events alone. For it is he alone through whom it is well with every creature, and without whom it is well with none, and from whom, and through whom, and in whom, are all things.
Therefore, since he himself alone is not only the beneficent Creator, but the most powerful lord, and most wise ruler of all; it is clear that it is he alone whom every other nature, according to its whole ability, ought to worship in love, and to love in worship; from whom all happiness is to be hoped for; with whom refuge from adversity is to be sought; to whom supplication for all things is to be offered. Truly, therefore, he is not only God, but the only God, ineffably Three and One.