In very broad strokes, the new adaptation of The Stand is a faithful take on Stephen King’s source material when it comes to the end of New Vegas: Trashcan Man brings the nuclear warhead directly to Randall Flagg, despite The Man In Black’s wishes, and a Hand Of God forms above the public execution that winds up activating the weapon and destroying the city.
For starters, the energy that winds up turning into the Hand Of God in the book is actually generated by Flagg – launched from his fingertip at followers who rebel against him (the appearance of the clouds as fingers in the adaptation is basically a substitute for this).
There are some key details that are changed, however.
Furthermore, the whole bit with lightning strikes killing individuals in the panicked crowd – including Lloyd Henreid and Rat-Woman – is original, as the big “finale” actually plays out very quickly once the miracle shows up.