In this section of Acts, Paul is addressing the intellectuals of Athens. They worship multiple gods and statues of these gods are located throughout the Greek city. Paul begins his exhortation by exposing misunderstandings about God. His first argument was to affirm that God is the creator of all things and that He does not live in temples. Nor does He need a temple to live in.
People may pride themselves in serving God, but it is God who serves humankind. If God is God, then He is self-sufficient and needs nothing that we can supply. Not only do the temples not contain God, but the services in the temples add nothing to God! In two brief statements, Paul completely wiped out the entire religious system of Greece!
It is God who gives to us what we need: “life, and breath, and all things.” God is the source of every good and perfect gift (James 1:17). He gave us life and He sustains that life by His goodness (Matt. 5:45). It is the goodness of God that should lead men to repentance (Rom. 2:4). But instead of worshiping the Creator and glorifying Him, humans worship His creation and glorify themselves (Rom. 1:18–25).
Paul’s point is that God is the sustainer of all things. God sustains his creation. It is not that we provide for him; he provides for us.
There is debate as to whether creation was made once for all, after which God let it go, or whether God sustains it constantly by what might be called “moment by moment creation” or “continuous creation.” Did God create the world and then just continue to preserve and guide it? Or does he constantly re-create it in the sense that if God stopped creating it for even a single instant everything we know would disappear? But I know that in the first chapter of Colossians Paul says that “in him [that is, Christ] all things hold together” (v. 17). That seems to suggest that if the Lord Jesus Christ were not holding all things together everything would fly apart.
I think Paul proclaimed in Athens a God who not only created all things but who also sustains them, perhaps not by a “moment by moment” creation, but at least by continuing to give the universe and world stability. The very fact that we and the world are here, that we are alive, and that we can think about both it and ourselves are all due to the sustaining activity of God.