Ron,
I've had a number of similar experiences, and it's the reason I've spent a lot of time running practice groups for rank beginners. The fundamentalists are my people; I understand their concerns, and God has granted me a measure of success in showing them how what I do fits into a thoroughly Christian life.
And then they say, "Will you teach me?" It often turns out that they want to be able to protect themselves just like anybody else, but they haven't felt that martial arts training was spiritually safe, and being unable to do it with a clear conscience, they didn't. Show them a way forward that doesn't have that problem, and many of them will take it, and find great joy in it. Of course, this is unconscionable to the demagogues who've been preying on their fears, which warms my heart to no end.

A lot of them still won't go down to the local dojo, at least for a while; they're afraid they'll unwittingly take part in some pagan ritual or whatnot, which fear is exaggerated, but in my experience not entirely unfounded. It's a matter for discernment, and Christian fundamentalists tend toward quarantine rather than discernment -- it takes a while to get them up to speed; they haven't had any practice. And at some level, they know it.