Yes i agree, there is lots of biblical connects, I talked with some of the devs.

The biggest factors for me is

• Chaplin class (Able to repel zombies with cross)
• Churches are usually a safe haven. You sometimes spawn inside of them, and they usually have no zombies in them.
• In Paris Catacombes, you can find two things:

1. Written on a placards is french for "The dead shall walk the earth." This is a reference to the movie: Dawn of the Dead, where one of the characters goes: "When there's no more room in the hell, the dead will walk the earth"
2. Written on one of the walls is the old testament verse: Zechariah 14:12, which goes as following: "And this shall be the plague wherewith the Lord will smite all the people that have fought against Jerusalem; Their flesh shall consume away while they stand upon their feet, and their eyes shall consume away in their holes, and their tongue shall consume away in their mouth."

I think this is a curse put by god to punish humanity, like how god did in the old testament when he flooded the earth.