Feser is a former atheist and now conservative Catholic (you can see why I like him).
Feser on God as Creator:
For the Thomist, to say that God is the First Cause of things is, first and foremost, to say that He is the cause of their existence at every moment at which they do exist. God creates things out of nothing precisely in the act of conserving them in being, and apart from His continual causal action they would instantly be annihilated. You, the computer you are using right now, the floor under your feet, the coffee cup in your hand – for each and every one of these things, God is, you might say, “keeping it real” at every instant. Nor is this causal activity something anything else could either carry out or even play a role in. Creation – which for Aquinas means creation out of nothing – can be the act of God alone.
Where creation is concerned, then, God is “first” cause not in the sense of coming before the second, third, and fourth causes, but rather in the sense of being absolutely fundamental, that apart from which nothing could cause (because nothing could exist) at all. As serious students of the Five Ways know, the sorts of causal series Aquinas traces to God as First Cause are causal series ordered per se, not causal series ordered per accidens. In the former sort of series, every cause other than the first is instrumental, its causal power derived from the first.... But where creation is concerned, Aquinas’s talk of intermediate or instrumental causes is only “for the sake of argument”; his point is that even if there were intermediate causes of the being of things, the series would have to terminate in a First Cause. In fact there is and can be only one Creator and He cannot in principle create through intermediaries. (That is not to say that God does not work through intermediaries in other respects. We’re only talking here about His act of causing the sheer existence of a thing or creating it out of nothing.)
Feser observes that a genuine understanding of God's creative power is utterly inconsistent with Deism. God is the cause of existence here and now, not merely the cause of the Big Bang, etc. He is the ground of existence, and His power of creation is unique; he does not assemble. He brings everything into existence out of nothing, and maintains everything in existence.
This understanding of God's creative power, expressed perhaps most fully by Aquinas, explains the Lord's answer to Moses from the burning bush. When Moses asked God his name, the Lord replied : "I Am." God is not a "thing". He is not a part of creation. He is Existence Itself. In Aquinas' words, God's essence is existence.
So, while popular images of God as First Cause have Him knocking down the first domino billions of years ago, and while even Aquinas might seem to make of Him the distant terminus of a regress of simultaneous currently operating causes, nothing could be further from the truth. God’s relationship to the world is in Aquinas’s view much more intimate than that, indeed, as intimate as possible. At least where the sheer existence of things is concerned, He and He alone is directly causing them at every instant. He is, as the Muslims say, “closer than the vein in your neck.”