God has spoken;
Twice I have heard this:
That power belongs to God; ..."
Usually we look to God's creation to apprehend his power but here we are concerned with power in God.
Can we really speak of God's Power or is this concept for our understanding of His action as manifest in his creatures? In the Middle Ages, some thought that we should not attribute power to God because his action originated in his intelligence and will.
St. Thomas Aquinas admits that power is the manifestation of God's intelligence which directs and commands, but power cannot be separated from God. Creatures are receivers of God's power and principles of action emanating from their existence. God, on the other hand, is Pure Act or Actuality. God is the active principle and active power in the highest degree. Power is integral of his Being; He is the God of Power and Might.
"Active power exists in God according to the measure in which He is actual. Now His existence is infinite, inasmuch as it is not limited by anything that receives it, as is clear from what has been said, when we discussed the infinity of the divine essence (7, 1). Wherefore, it is necessary that the active power in God should be infinite. " (Summa Theologica, Part I, q. 25, Art. 2)
The power of God is that ability and strength whereby He can bring to pass whatsoever He pleases, whatsoever His infinite wisdom may direct, and whatsoever the infinite purity of His will may resolve. . . . As holiness is the beauty of all Gods attributes, so power is that which gives life and action to all the perfections of the Divine nature. How vain would be the eternal counsels, if power did not step in to execute them. Without power His mercy would be but feeble pity, His promises an empty sound, His threatenings a mere scarecrow. Gods power is like Himself: infinite, eternal, incomprehensible; it can neither be checked, restrained, nor frustrated by the creature. (S. Charnock).
C. H. Spurgeon states it well, "Gods power is like Himself, self-existent, self-sustained. The mightiest of men cannot add so much as a shadow of increased power to the Omnipotent One. He sits on no buttressed throne and leans on no assisting arm. His court is not maintained by His courtiers, nor does it borrow its splendor from His creatures. He is Himself the great central source and Originator of all power."