There is no change in God. However, as one person already remarked, here "change" has a very specific appliction. We think of the term 'change' as applying to activity (i.e., I changed my clothes, or I changed direction in the car, first going south, then going east, etc.). This is not the kind of change we are talking about, for otherwise, that would mean that God could not do anything at all. Rather, the following:
A person sees that a fisherman has slipped from the bridge and is hanging from the bridge by his ankle, and otherwise, will fall to rocks below headfirst. He acts immediately. He first runs in to get his rope, gauze, and peroxide, he then changed direction to go up to the bridge. He ceases running straight because he has to run vertically up the stairs (another change?). He then walks straight again. He then kneels down (another change in posture), ties a lasso in the rope as a harnass, and lowers it down around the head and up the midsection (more change), pulls the guy up, washes out the wound in the ankle, and bandages it (change change change). Again, in one sense we would think of this diversity of motion as "change." Yet in another sense, it was one singular unchanged action: saving the person. It was without change in the following manner, however, that this energy proceeded from a single will which did not change--the man neither changed his mind at any time about saving the fisherman nor did he change his action in such a way that the fisherman might not be saved. In fact, if his will would have changed, then his actions would not have changed (i.e. he would maybe have just run straight past the stairs up to the bridge, without a change of motion, but with a change of will, the latter being the more crucial in defining energy). An unchanging will necessitates variety in energetic application in order that the single will is carried out, and in this sense, is also a single energy or operation (i.e. the single energy/operation of saving the fisherman).
Thanks for those quotes, but do the energies change? It seems that they don't because according to St. John's arguement, the natural energy is is innate in the essence, so they can't change. Is this correct?
A good starting place for the answer to your question is St. John of Damascus:"The true doctrine teaches that the Deity is simple and has one simple Energy, which is good and energizes all things, just as the sun's ray, which warms all things and energizes in each in conjunction with its natural aptitude and receptive power, having acquired this form of energy from God, its Maker. But actions (Gk. praxis) are also called energies...and yet again, the result of the force is also called energy." (St. John of Damascus, 8th c.: Orth. Faith 1.10) "All the faculties we have already discussed...both those of knowledge and those of life, both the natural and artificial, are...called energies. For energy is the natural force and activity of each essence: or again, natural energy is the activity innate in every essence: and so, clearly things that have the same essence also have the same energy... no essence can be devoid of a natural energy." (St. John of Damascus, 8th c.: Orth. Faith 2.23)
Does this mean that God's energies change?
God cannot be restricted. There can be no change in the Godhead. If God were to restrict His power, He would no longer be omnipotent, and thus He could not regain His omnipotence, and thus all existence, including Himself, would be annihilated because of lack of support from an omnipotent being.Not true, God creating is a function of His Energy, not His Essence. There is no change in God when God creates a rock of any kind. So your argument against the creation of a rock He cannot lift by trying to apply a change in God's nature does not hold water.