To both questions the priests give a correct answer. Using the laws of clean and unclean, God points out a principle that applies to Christians today. Very simply, God says that it is impossible for God's holiness, in us because of our relationship with Him and the indwelling of His Spirit, to pass from us to the world. In other words, if a holy thing touches a profane thing, the profane item does not become holy.
On the other hand, the attitude of the world, if it comes in contact with His people, can pass from the world into us. Using the above wording, if a profane thing touches a holy thing, the holy item is contaminated. The spiritual principle for today's Christian is obvious: The world will contaminate your holiness, if you are not on guard against it.
Reading these verses from The Living Bible makes God's meaning very clear. Though it is not an exact translation, but a thought-for-thought paraphrase, the point is correct.
Ask the priests this question about the law: "If one of you is carrying a holy sacrifice in his robes, and happens to brush against some bread or wine or meat, will it too become holy?" "No," the priests replied. "Holiness does not pass to other things that way." Then Haggai asked, "But if someone touches a dead person, and so becomes ceremonially impure, and then brushes against something, does it become contaminated?" And the priests answered, "Yes." Haggai then made his meaning clear. "You people," he said (speaking for the Lord), "were contaminating your sacrifices by living with selfish attitudes and evil hearts—and not only your sacrifices, but everything else that you did as a 'service' to me." (Haggai 2:11-14)
The people, having absorbed the prevalent attitude of the world, became infected by it. As we have seen repeatedly, their relationship with God quickly deteriorated into estrangement—just as the Laodicean's does.