Pastor Bryan Chapell writes in his recent book Grace at Work:

I have a friend who's a marathon runner. He was in a race a few years ago that he knew would be tough, particularly at the end. And knowing what happens at the ends of races, how people call out encouragement, he didn't put his own name on his racing bib but actually wrote the word “Christian.” He knew that when he got to that final mile, and all the people were cheering, they wouldn't call out his name but would say, "Go get `em, Christian!" "You can do it, Christian!" "Hang in there, Christian!" He ran to represent the name of Christ that he bore.

Possible Preaching Angle:

Colossians 3:17 tells us: "Whatever you do, in word or deed, do everything in the name of the Lord Jesus." Everything you do should be in the name of Christ. When we are in the workplace, we bear the name of our Savior. Because we represent Christ, we don't cheat the boss on our timecards or on expense reports, even if others do. We don't lie to the IRS. Why? Because our Lord has written his name on us so that others can see him.