Verily I could quote every other line from Mr. Javerbaum’s annotation of the Scriptures and gather a chuckle, so deliriously funny is he as a sort of amateur theologian and stand-up comedy genius rolled into one. But this wouldn’t be fair. It didn’t make the Top 10 this time around, but when God gets around to another set of laws, “Thou shalt not sprinkle reviews with too many spoilers” might just make the cut.

And while Mr. Javerbaum’s book (inspired by a series of tweets), from which most of the material in the show is culled, is sensationally funny, at nearly 400 pages it goeth on a bit. (Not unlike the Bible itself, of course.) At the risk of blasphemy, I’ll aver that “An Act of God” the Broadway show is more fun — and certainly a brisker entertainment experience — than “An Act of God” the book.

This is due in no small part to the perfection of Mr. Parsons’s performance. With his sly smile and his sparkly eyes, he delivers the zingers with an easy grace, giving a nice silky consistency to shtick that, in more aggressive hands, might grow oppressive. He handles the pseudo-biblical language as if it comes as naturally to him as the nerd-speak he spouts on television, looking down upon us with an air of benevolent affection, like a really caring therapist, but one who prefers to talk about himself.

Mr. Parsons’s light Texas drawl makes the Lord seem approachable as opposed to unfathomable, just a nice fellow sitting on the porch — a very fancy one, mind you — sharing homespun if definitely holier-than-thou wisdom about, well, just about everything to do with his ways and his world: Noah and the flood (that business about all the animals was an error; really there were just a couple of puppies); Abraham and his near-sacrifice of his son Isaac (“It was only then that I first began to consider the possibility that there was something seriously wrong with me”); the taking of his name in vain (“Kanye, next time you win a Grammy Award and you thank me for your ‘God-given talents,’ they’re going to get God-taken, understand?”); the weirdness of a child’s bedtime prayer (“Even I consider it bizarre that the last words on children’s lips before they go to sleep would address the prospect of their own premature death.”)

Forgive me. I have sinned and spoiled, but these are merely a few morsels of the veritable flood of funny lines in the show, which has been directed with a sharp eye by Joe Mantello, and which takes place on an eye-dazzling set by Scott Pask, reminiscent of both James Turrell’s recent Guggenheim exhibition and the design ethos of Busby Berkeley musicals.

As it happens, “An Act of God” ends with a soft-rock song, in which God tells us that we’re on our own, and it’s time we stopped looking to him for advice and got our act together by ourselves. Turns out God can’t really carry a tune too well, but it’s a comfort to know that even he isn’t perfect.