'Unclean' in the Bible

So Haggai responded, "If someone who is unclean because of contact with a dead body were to touch any of these things, would they become unclean?" The priests responded, "They would be unclean."

Then Haggai answered, ""That's how I look at this people and this nation,' declares the LORD. "And that's how it is with everything they undertake and with what they offer there it is unclean.