Is it technology with nothing to worry about or is it a serious risk to Christians?
It's something to be concerned about, but interpreting a first century text as a warning against RFID tags seems a little paranoid. I would be far more concerned about the potential for violations of civil liberties. If and when these tags are used on humans, the person in question should have complete control over them, with the ability to both monitor and regulate access to the tags and to turn them off altogether. There should also be zero tolerance for any government tracking, for any reason whatsoever, even to prevent a crime or terrorist attack. But, as long as basic privacy concerns are met, RFID tags represent the first step in what could be a great advancement for humanity. A RFID tag that can open doors or carry medical information may not be that big of a deal, probably not something people are going to cash out their savings to run and get. But what about a phone with an implanted speaker and earpiece...now your talking about something I might want. Some research is going on that would allow us to superimpose an electronic projection (a computer monitor, perhaps?) on the retina, I know something like that would eventually take off.
Technologically, this is nothing but a collection of transistors: copper, silicon, etc. It would be absurd to think there's something wrong with these tags in and of themselves, but we must always be on the guard against those who would do anything to increase their power at the expense of human liberty.