Hard to give much good advice without more specifics, but it sounds like this is more a conflict of feeling like a lesser Christian because you don't feel compelled to confront all the non-Christian things surrounding you. And I would say that your loyalty to Christ is proven more by your actions and your conduct than by the arguments you get into (or win). And I'd say your best bet is to focus on showing the fruit of the spirit as much as possible. So be loving, joyful, peaceful, patient, kind, virtuous, gentle, faithful, and self controlled. If you do that and do that well, people who are paying attention will notice and perhaps in time you'll be in that situation described in 1 Peter where people are asking about the hope that you have, and you'll be able to answer them with gentleness and respect. The other advice I'd have, is to ask God to remind you as often as you need it, that even the worst and most antagonizing of your co-workers is someone that he loves and longs to rescue from their sinful, empty way of life.
And get yourself some positive peer pressure, a good small group or sunday school class or CC forum friends; but find a way to add people to your life who will reinforce and refine your values and convictions to be more and more like Christ. Daily Bible reading and prayer helps, but community is also essential.