Remove a sentence if it contains a word.

[lokhtar]

I have a paragraph, contained in a string variable, that looks like this:

This is an example of a paragraph that I have. I would like to remove any sentences containing certain words, for example the word bad, or naughty. If it has bad, I don't want it. If it doesn't, I want to keep it.

I want the string to become:

This is an example of a paragraph that I have. If it doesn't, I want to keep it.

I could use any help!

Thank you in advance!