Peter Kreft got it from St. Thomas Aquinas ( it originated with Aquinas)
The argument from change (or motion)
1) things in the world are in motion.
2) everything in motion was moved by something else, and that was moved by something and so on.
3) motion must have a starting point.
4) There must be a first mover not moved by anything else
5) God is the only being that is capable of being an unmoved mover.
6) therefor, God exists.
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Aquinas' "cosmological argument" begins to fail at #4 and gets worse from there. Which is why there are a hundred modern variants such as Kreefts' that try to disguise some of it's weakness. All of them pose that there is a "first cause" and that that first cause is, of course, the god/gods of their choice. All of them fail to prove that a god or any theistic gods exist.