This was initially planned by the first screenwriter as a tongue-in-cheek Prize Fight: Arnold VS Satan, Arnie telling his opponent to go straight to Hell. He didn't exactly know how this hilarious format would develop but had a go on Arnold, who liked the idea. Unfortunately someone got involved taking it way too serious. It could have been great fun, but ended up being the most embarrasing of Schwarzenegger's movies, making Kindergarden Cop seem almost academic in comparison. It's also a very dark movie, even the forced one-liners contain no comic relief whatsoever, only raw cynicism.
A lot of wasted effort has gone into this one. Gabriel Byrne has the perfect face for the role of Satan, but acts as if he's bored to death, which is understandable. The screenwriter and the director haven't the faintest idea of what christian theology is about, although I'm sure a lot of illiterates brainwashed by Sunday school will think otherwise. In the New Testament the "End of Days" is of course God's design, not Satan's, he's actually trying to prevent it by tempting Christ to abandon his destiny. It's Hollywood, sure, but does that make it okay, that we are led to believe that theology is gum wraper?
The only good scene in the movie is three seconds long: Satan reveals his true majesty as a growing shadow on a wall, spreading his butterfly wings over a church altar. It's a very impressive sequence, quoting Fantasia, but when we get a good look at him it's pure Nintendo.
Schwarzenegger apparently enjoys acting as a Vicarius Christi in this ambitious piece of hokum and actually seems quite devoted to his character, but the pompous seriousness of the whole affair is really what makes it so unbearable.