No, I think I've resolved that one in my mind, although if you're using the government's fiat currency with Washington's face on it then you have to render to Washington what is Washington's. All the more reason to transact in Bitcoin.
I'm referring to other passages like Romans 13:7 - "Pay your obligations to everyone: taxes to those you owe taxes, tolls to those you owe tolls, respect to those you owe respect, and honor to those you owe honor."
And there's an example in the Gospel where Jesus paid a tax even though He made the point that He didn't have to, just to avoid offending people, presumably thereby setting an example.
When the Jews indicted Jesus in front of the Roman governor they accused Him of opposing payment of taxes to Caesar (Luke 23:2), among other things. The question is, did they misunderstand what Jesus had said about "render unto Caesar...", or did they have it right in this case?