Full Idea
The fact that heaven and earth are there proclaims that they were created, for they are subject to change and variation; ..the meaning of change and variation is that something is there which was not there before.
Gist of Idea
Heaven and earth must be created, because they are subject to change
Source
Augustine (Confessions [c.398], XI.04)
Book Reference
Augustine: 'Confessions', ed/tr. Pine-Coffin,R.S. [Penguin 1961], p.256
A Reaction
It seems possible that the underlying matter is eternal (as in various conservation laws, such as that of energy), and that all change is in the form rather than the substance.