Demetrius and the Gladiators (1954)

Continuity mistake: Caligula orders his chief gladiator to kill a prisoner so he can test the Robe's "powers". The gladiator stabs the prisoner with a dagger and straightens up. Look at the dagger and you'll see no blood on it.

Factual error: There is a shot of a large arena where gladiatorial combats take place. Arranged around the top of the arena are a number of classical statues, one of which is Michelangelo's statue of David circa 1505 AD, 1,465 years too early!

Messalina: Don't you find him interesting?
Claudius: He's a remarkable young man. He has something that Rome has lacked since the early days of the republic, something to believe in - faith. Our early conquests weakened it. My family, we Caesars killed and buried it. Strange if the memory of a dead Jew should bring it to life again. Messalina, don't hurt him. Don't destroy what he has.

Messalina: What is your name?
Demetrius: Demetrius.
Messalina: You spoke of a god, Demetrius. Which god?
Demetrius: There is only one God.
Claudius: He's one of "them." This is very interesting. A Christian.
Messalina: Are you a Christian?
Demetrius: Yes.
Messalina: And you won't fight?
Demetrius: No.
Claudius: He can't my dear. It's against his religion to kill.

Messalina: Why did you run? I don't think you're a coward. You had no real chance of escaping, you must have known that.
Demetrius: This is a place where men are trained to kill each other like animals.
Messalina: And men aren't animals?
Demetrius: No.
Messalina: We admire a magnificent animal who fights. Why not a man who fights?
Demetrius: Because God did not put man on earth to destroy his own kind. Nor a woman to enjoy their agonies as they die.