Statesboro, GA, USA
I think there's another problem at hand.
To "leave one's religion out of the workplace" doesn't mean that for a Christian. What do I mean by saying this? I mean that it can only be considered mere "religion" by those who don't believe. For the Christian who believes the central teachings of the Bible as true (really true) then it is not a "religion" but looking at things in the right way, doing things in the right way, as revealed by God.
I know that rubs agnostic thinking the wrong way, because the agnostic's claim to truth (or God who is the foundation for truth), is the very uncertainty of those things. Therefore, for one to say "I know. I really know", sounds arrogant to agnostic ears. But the assumption of most agnostics, I imagine, is that "I don't know, so he or she surely can't know either". In fact most agnosticism that I have encountered is just as dogmatic as Christian beliefs. It doesn't amount to believing merely that "I don't know, or I can't know", but it amounts to believing "no one CAN know". I just wanted to point that out to illustrate where the rub is for both sides. Both believers (in dogma, or the dogmatic uncertainty of dogma) are diametrically opposed in their presuppositions.
Also Christians have this odd belief that they are suppposed to bear witness to THE truth. (not the preferential individualistic kind of truth) but the overarching kind of truth that is true, regardless of popular opinion. They also have the odd belief that they are supposed to (by the help of God himself) in their every day lives, witness not only to cloistered little groups of already believers, but to their neighbors, coworkers, friends, enemies, etc... of this truth. All of these "odd" ideas come from the Bible, which most Christians believe is the rule of faith, and the recorded revelation of God for their lives. So Christians, by definition of their creed, are already set up to believe that if they "leave their religion at home", they are failing to be true to their Lord. Christians also have the odd idea that sometimes they will indeed be not liked for their peculiar views, or public expressions of their religious beliefs. And not that it might happen, but that it will happen from time to time, unless they are so quiet a Christian that they make no waves (in which case they are not really being true to their beliefs). So seeing this is their creed and the teaching, isn't the conflict sometimes understandable?
Now does that mean that Christians are to be always overtly overbearing with their witness? No. Some of the best witnesses of the truth of God, (in my life) have been from others who are simply quietly radiant with love for God and others, issuing in a lack of focus on themselves. For Christians also have the odd idea that their words are not unimportant, but LESS important than their deeds. So respect, fairness, consideration of feelings, and all those kinds of things can still be present without "leaving your religion at home".
Having said all of that, I would like to say that your refusal to comment on someone's piety, is not a bad thing really. In fact it is an honest thing. How can you praise something you're unsure of, or something that you have some problem with? That would be hypocritical wouldn't it? One way to describe it, is that they have asked you to "leave your agnosticism at home". And you can't. Because, it's really what you feel. But maybe seeing that's why you feel uncomfortable, can help you relate a little to the other side. For neither can they leave their innermost beliefs at home. For beliefs, one way or the other, are made for living.