A recent study mentioned at gamepolitics.com indicates reading passages from the bible can make people more aggressive. I'm happy to hear of this study, because it's something to bring up when people claim violence in movies or video games increases aggression.
Of course, like studies that link video games to aggression, all this measures is a sort of immediate reaction in a non-critical situation. It doesn't really prove the bible makes people violent any more than other studies prove video games make you violent. No, the proof that the bible makes you violent is all those people who specifically say they're killing people in the name of God. Which is a notably greater number than that of people claiming they're killing people in the name of Grand Theft Auto.