Christian Imagery
Holy imagery, Batman. And we mean that literally.
There's a cross here, a cross there, and a Christ image over yonder—the movie Frankenstein opens in a graveyard, and there's Christian symbols all over. In fact, Frankenstein and Fritz can barely shovel a spadeful of dirt without hitting one.
The Christian images are a way to contrast with the devilishness of Frankenstein; he's defying God (not to mention common decency) by digging up dead bodies under a cross. The Christian symbols show that Frankenstein is a blasphemous—and egomaniacal—jerk.
This is underlined by the way Frankenstein warps Christian theology in order to make it fit with his whole mad-scientist steez:
"He's just resting, waiting for a new life to come!"
This is what Frankenstein says of a dead body while clutching the coffin. He's planning to put himself in the place of God; he's planning raising someone from the dead. But here's where the Christian imagery and allusions in Frankenstein start to get uber interesting.
Because you know the most famous Biblical incidence of being raised from the dead, right? Yup: that'd be Jesus C. himself.
Wait, though: if Frankenstein is playing God by raising the dead, than the Jesus figure would be…
The monster. In this movie, the monster is a Christ figure.
And there's more evidence of this than just the fact that he gets resurrected. In the iconic scene where the monster reaches towards the light, he seems to be praying. And then, of course, at the end of the film, the monster is killed—he's an innocent and an outcast, but he's killed for Henry's sin of defying God.
However, seeing the big, ugly, murdering monster as Christ is close to blasphemous in itself, and James Whale doesn't push the comparison too far. That would have been a career-killing move in 1931. But the parallel is as prevalent in background of the movie, much like all those crosses around Frankenstein and Fritz as they dig.