1) They are not entitled to the truth
2) I'm not sure we're entitled to lie
You could pre-arrange some sort of a code word or signal so all the Jews sneak out the back door...
Then tell the nazis there are no Jews in your home. If that doesn't work, I'd say protecting the oppressed is within your God-given rights (lethal force if necessary).
Another option...for the theologically inclined...if you know that these Jews are not Christians...I'd tell the nazis you're not *hiding* any Jews...b/c we know a Jew is one who is *inwardly* and not outwardly...so Christians are "Jews"...and since you're answering the door, and consider yourself a "Jew" in the New Testament sense, you are not hiding
So I guess you could honestly answer you're not hiding any Jews and wait and see if they ask what you mean by "Jew".
I think I solved the dilemma (except for dispys!)