Cleanliness and Uncleanliness
We understand the common uses of these two words, but Biblically speaking, what do they mean? And is that meaning applicable today?
Repeatedly these verses state that whosoever touches something that is unclean, is made unclean. So physical contact is all it takes to make something that is clean, become unclean. In each case, that which has become unclean, is only unclean until the evening - provided that person's clothes have been washed.
This verse indicates that if someone touches something that is unclean by accident, that person is then unclean. The word guilty is also used. This appears to mean that intent doesn't matter. A person could be walking along doing the most noble of acts. The moment they accidentally touch the unclean thing, that's it, they are unclean.
Now lets compare this with our natural world. Suppose a healthy person comes in contact with an unhealthy person who has a disease, like the flu. Which is more likely to happen, does the person with the flu get better because of the contact, or does the healthy person get sick because of the contact? Hopefully the sick person eventually does get better, but it has nothing to do with coming in contact with the healthy person. What typically happens is the healthy person gets sick. That is how the flu travels, from the unclean, to the clean.
This is applicable to the Christian in a spiritual sense. We have all come in contact with that which is unclean. When we do, we are guilty. However our clothes are washed, and we are once again made clean.