Forget the mark of the beast stuff, nobody (except perhaps people serving time for violent crimes) should be forced to have a chip implanted in their body against their will simply on the grounds of upholding personal freedom.
I would agree on the personal freedom that you're talking about -- but at the same time -- the Bible makes it clear that there is going to be such a thing and that it's associated with the Antichrist and his one-world government -- and in that government there will be no personal freedoms.
Even if the Bible didn’t say that, it should still be opposed on the grounds of personal freedom. Only (some) Christians would be persuaded by an argument against this based on one interpretation of a verse, but everybody can be persuaded on the grounds of personal freedom. Know what the Bible says is good, know WHY the Bible says what is says is better.