Colossians 3:22
"Servants, obey in all things your masters according to the flesh; not with eyeservice, as menpleasers; but in singleness of heart, fearing God:"
A good work ethic is important to your Christian testimony.
There are people with whom you work who are lost. Your work ethic may be the very thing that causes them to get saved. I have watched Christians use their Christianity to be lazy on the job, and that only hurts the cause of Christ. The people who ought to have the best work ethic should be God's people.
In the verse above, God deals with the employee. The two key words in this verse are "servant" and "masters." The "servant" is the employee and the "master" is the employer. God shows in verses 22-23 what this relationship should be like.
First, you must understand your role if you are going to be what you should be for Christ. As an employee, you are a servant to your boss. It is important for you to understand that you work for your boss and they don't work for you. Most workplaces are filled with criticisms of how bad the boss is. Let me remind you, you are the servant. Your boss owes you a paycheck and you owe him hard work. Stop griping about what your boss doesn't do for you and remember that you are his servant who is supposed to work hard.
Second, be obedient to your boss. Look at what the verse above says, "Servants, obey in all things..." It didn't say to obey in the areas where you like, but in all things. If your boss gives you a dirty job, do it with the right spirit. Stop complaining about always getting the worst jobs and be thankful that you have a job.
Third, don't work as a manpleaser. You will often find people who tend to flatter the boss for the sole purpose of moving up the ranks. God is teaching that you should not be one who tries to flatter your boss so you can get position. In other words, stop being a brown-noser. Don't talk bad about your boss, but also don't flatter him for the sake of position. Work for position instead of trying to flatter them for a position.
Fourth, give your best effort on the job. Verse 23 says, "And whatsoever ye do, do it heartily,..." Every day you should give your best effort on the job. Every Christian should be the hardest working person in their place of employment. Your job is not to witness to the lost while you are working, but your job is to work hard. Witness at break time and when work is over, but work when you are being paid to work. Give your best effort everyday.
Fifth, always remember that how you serve your master is how you serve the LORD. Notice that verse 23 says, "...as to the Lord, and not unto men;" Friend, your work ethic reveals your Christianity. If you don't work hard, then you are a poor Christian. Your boss may be lost, but they're position is representative of Christ.
If we went to your place of employment to determine your Christianity, what would we find out? Does your work ethic match how you display your Christianity at your church? There is no room for laziness in Christianity. God expects you to work hard. If you want to please God, then everyday go to work and be the best employee. That is good Christianity!