One reason that Paul may have spent what seems to us to have been an inordinate amount of time discussing God’s power is because his audience included so many pagans or former pagans. Consider, for example, his speech on the Areopagus to the Athenians (Acts 17:24-29), or the assertion in his letter to the Ephesians (4:6) that there is “one God and Father of all who is over all and through all and in all.”
In the West now, people readily concede that, if there is a god at all, He is something like the God of Jews, Christians, and Muslims. He is not, that is, like Jupiter or Zeus — whose powers were great but still limited.
I remember being surprised when I read a passage in the Iliad about the Greek warrior Diomedes wounding Aphrodite. Whaaaaaat?? That would not have happened with Yahweh: If He decided to show up at a battle, nobody would wound Him — that’s not how He rolled. The battle would be over and everyone who wasn’t killed immediately could go home early.
So this new god was different for the pagans that the Apostle to the Gentiles was addressing, and that had to be explained to them.