When I started grad school I tried to start a t'ai chi ch'uan club on campus. I put up flyers on my office door with a sign-up sheet. These flyers had a picture of the yin-yang symbol (called t'ai chi) on them, as well as two outlines of a famous t'ai chi ch'uan practicioner in some postures.
A fellow student who, later I found out, is an extremely literal Christian, comes over and asks me what t'ai chi is. OK, that is a reasonable question.
I explain to him that it is a Chinese martial art, exercise, and meditation which can be based on the theory of yin and yang (but one doesn't have to look at it in this light at all), and is typically done slowly, but also done quickly, for example, for self defense purposes. It has benefits of improved balance, precise alignment, weight bearing activity, relaxation, and cons of probably not cardiovascular exercise, not immediate self defense skills, not much sparring, and difficult to find a good instructor (there are more benefits and cons that I am probably leaving out). I wasn't in salesman mode, but rather I presented a very fair view of what it is. Afterall, I didn't need him to sign up as I already had about 5 or so signatures at the time, and you only needed 10 to get your club proposed. I was happy that I had that many signatures; afterall, my office was sandwiched between the statistics dept and the math dept.... not exactly the hang out spot on campus.
Anyway, I then demonstrated a few basic postures and applications of these postures for him.
He then, very suprisingly and without warning, proceeded to tell me how the yin-yang symbol is the root of evil, and Jesus is the only true way! He said something about the armor of God being all the protection one needs.
I asked him what Jesus had to do with anything in this case since we were talking about a martial art, not a religion, told him that I was honestly a bit confused by his remark, and said that if he wanted to, he is welcome to come and watch the club in action and participate, if the club gets enough members to get going that is.
I also mentioned that Jesus' teachings at least, from what I know, don't seem to contradict anything in t'ai chi ch'uan or any martial art that I am aware of. Moreover, heh, didn't God/Jesus create t'ai chi ch'uan in the first place!!?

(I didn't ask that though)
For fun, I should have asked him if he'd be interested in putting his armor of God up against some evil t'ai chi ch'uan punches/kicks.
Every month or so I'd get a new very small green Bible slid under my door from you-know-who. Since I actually don't mind the Bible and don't feel insulted by them, I thanked him for the first one (he denied sending it, even though I saw him placing exactly the same type of Bible in the computer lab). I was only insulted by him thinking I threw them away when he gave them to me.
He'd also ask me 'why do you read that stuff?' whenever he'd see me read JREF commentary and CSICOP magazines/articles that I'd bring or print out and read. He didn't notice at all until he saw I had articles on religion.

I'd tell him the same thing each time, that I find it interesting, entertaining, and it works my brain, like the statistics and mathematics we were studying in grad school. What he wasn't aware of, or if he was he actively chose to deny it, is that I think the exact same way about articles on religion, and also printed out a lot of these to read.