Skepticism at work

I'm currently at a loss as to how to approach skepticism at work. Do I tell them, or keep it secret?

At the moment, my work life and Jewish social life are completely separate. I can keep it that way as we don't have such a social culture at work. Occasionally we go out together but no one expects to be invited to your birthday party.

I've always been vocal about my Judaism. I don't go on about it unless people ask questions, but I've never lied about why I can't go out on Saturday night or eat out with non-Jewish friends (unless they care to come to one of the few, fairly poor, kosher establishments that are available here). So everyone at work knows that I keep Shabbat and kosher. There are only two other Jewish people in the company, neither of whom are frum.

On the one hand, it would be nice to have a few friends at work who know where I stand. Many of them are atheist and it would be nice to be able to have some good discussions along those lines.

On the other hand, there are a few reasons not to tell. I still have a lot of respect for Modern Orthodoxy (or Open Orthodoxy, I think I fit better there) and I don't want to present it in a bad light. I guess I feel like it would be a chilul Hashem, a disgrace of God's name. And of course I don't want to seem fickle. Especially to the Christians at work. I wonder how they'd react. (I do occasionally mention my dissatisfaction with the politicization of Judaism, especially kashrut. But that's about all.)

But here's another reason. One of the other Jewish people in the company works in my department. He's very culturally Jewish, but completely atheist and eats ham on pizza (he says that the god that he doesn't believe in lets). And then there's me, who outwardly (and until recently, inwardly) was completely frum. I cover my hair and only eat kosher. And we're good friends, and I liked presenting that to the others. Just showing the range there can be.

So for now, at least, I suppose I'll retain my orthopraxis at work, and in various other environments where there wouldn't be repurcussions in the Jewish community as well. But I do feel a little cowardly about it.