Answer with Grace

Grace gets her very own blog post, because she is the first to post a question here. Thank you, Grace.
If you want to phrase it Biblically, you are correct - answer the fool by his folly.
If you want to phrase it in more general terms: do not let people abuse language. It is not merely a tool of talking, but of thought, and has a tendency to do our thinking for us. If we are not careful, we will end up being a slave to thoughts, as the uneducated, foolish, or ignorant often are, and even the wise at times. We have to know how our own minds work, and others. Do not let unbelievers (or Christians for that matter) use words one way over here, and another over there. Don't let people mythologize when it suits them against your strong argument, and be objective and subtle when it favors their own weaker argument. For example, Christians tend to think Milton was orthodox, while unbelievers try to read all kinds of Satanic approval into his work, or make him into Prometheus, or just throw him out of the canon so they can talk about the latest hot topic. Don't let either side do this. It's the only way to do good scholarship. Hold people's feet to the fire about the way they use words, because, generally speaking, its abuse of language that precedes abusive language, and murder of accepted meanings that leads to murder outright. This means that Milton ought to be read as he intended, as close as we can get. Anything else is laziness at best. So intention holds, and it ought not to change from argument to argument, or text to text. Christians will benefit far more from the fair use of language, logic, and facts than their opponents. This may entail repentance, on our part, from intellectual sins like distorting language, but, in the long run, will undermine our opponent far more.
Cheers and God bless.