In the workplace, if you profess Christianity, your coworkers will be watching you closely. There is a desire to see if you are just like everyone else. They want to see if you will say one thing with your mouth and do another thing with your actions.
There is also a great misunderstanding of the gospel in the secular world. There is an idea that being a Christian is all about being a good person or at least looking like you are one. And I think professing Christians often perpetuate this idea. Our coworkers see us "being good" but they don't see us confessing our sins and explaining where our forgiveness comes from.
I have recently taken Biblical language to the work place. One area where I practice this is in the area of apologizing. Instead of spouting off a quick "I'm sorry", when I wrong someone in the work place, I name the sin I have committed (I was selfish) and ask for forgiveness (will you forgive me?)
I have found it very difficult to do this in the workplace. I feel exposed. My coworkers don't know how to react to it. But, I have also found it allows me to open the gospel door in conversation. When my actions are being quickly dismissed because the situation is awkward for those involved (including me), it gives the opportunity to explain that my offense was first against God, and the condition of my heart matters very much to him.
Do not underestimate what God can do with your sanctification process in the workplace.