Seriously. God could have resolved the whole situation with an easy flex. Honestly he has really poor emotional control issues. Let’s imagine how he could have handled the situation better.
So he’s there. He’s sitting there on the mountain, watching them spend years building their tower up. Finally, after decades of effort, the tower is nearly complete. As the last exhausted mason finishes the last stone, he looks out, near eye-level with God. He’s about to ask God, “not so great now are you?”
But before he can, God looks on amused. Then he just laughs, taps his foot, and the mountain he’s on instantly grows a hundred times taller. The mason, and all the humans, suddenly know just how comically beneath they are to God in ability.
That’s how you put a mortal in their place without being a dick about it.
If this were KSP, I would drop the station with the kerbonauts inside, just to see if any kerbals manage to cheat the physics engine enough to survive reentry and landing sans parachutes.