The concept of freedom implies restrictions of some kind because within the concept there is a silent question, "Freedom from what?" In other words, it's a human concept which does not apply to God without qualifications. So, what is the meaning of God's freedom? It is the freedom "to be" in the absolute sense of the word. God is the fullness of Being without limitations; limitations can only be a predicated of creatures. There is no being and non-being in God- just Being because "being and non-being" is a dualistic way of thinking which does not apply to God. Karl Barth has well written, "Freedom in its positive and proper qualities means to be grounded in one's own being, to be determined and moved by oneself. This is the freedom of the divine life and love. In this positive freedom of His, God is also unlimited, unrestricted and unconditioned from without." (Google Books: Karl Barth, Church Dogmatics, Vol. 2, Part I, p. 301) You say God is not free because he cannot do evil against himself! God is the fullness of Being while evil is the absence of some goodness. If God could do evil against himself, He would be less good, therefore not God. God does not contradict himself. Freedom consists in the ability to act according to one's true nature be it God or man.

A difficult question has been raised, "If God was absolutely free to either create or not create the universe, does that mean that prior to creation God did not know if the universe would exist?" Again we are applying to God our dualistic way of thinking. St. Thomas states the following, "Before the world existed it was possible for the world to be, not, indeed, according to a passive power which is matter, but according to the active power of God...." (Summa, Part I, Q. 46, Art. 1, Reply to objection 1) By an act of God's will the possible reality of the universe came into being with time. We cannot say that creation came into being at a particular time because time begins with creation, so "In the beginning God created the heavens and the earth." (Gn1:1) is the only proper expression. The freedom of God remains a deep mystery which many philosophers have tried to explain. To understand it fully we would have to see God's Freedom in relation to his infinite power, wisdom, love and all other attributes which is a tall order for the limited human mind.

 

For me, the blue sky suggests the freedom of God. It appears as unmoving, ever present and without limits against which the clouds (creatures) enjoy a relative freedom. Karl Barth has well stated, "The divinity of the freedom of God consists and conforms itself in the fact that in Himself and in all His works God is One, constant and eternal, and therewith also omnipresent, omnipotent, eternal, and glorious."
(Google Books: Karl Barth, Church Dogmatics, Vo. 2, Part 1, p. 440)

 

2. Freedom of Creatures