To resolve this problem, we must affirm that creation, meaning the bringing into existence of things from non-existence, cannot properly be called a change. We have reasoned rightly when we say that the subject of change cannot be produced by the change, but we have also reasoned rightly when we say that all things, inasmuch as they have real existence, are created by God. Change as such, then, cannot include the bringing into existence of things that previously had no existence, even in potency.
This error, like many others, is partially caused by our imagination. We imagine something as a sort of being even though it does not exist, a non-existent being, and then we imagine it being brought forth from this state of non-existence into existence. In other words, we imagine that something persists during a transition from non-being to being. Before this tree existed, for example, it was a tree that did not exist. When God created it, it became a tree that exists. This approach is mistaken for the simple reason that before the tree existed there was no tree.
Going from non-existence to existence only resembles change, which is why we call it a change. In reality, though, creation is not a change but a relation of the creature to the Creator.