Few things can be more grievous than to be bossed around by someone who has no regard for God, the things of God, or the people of God.  An unsaved boss might demand that you misrepresent the truth, in order to make a sale or avoid some difficulty.

Make up your mind in advance what you will, and will not do, in certain situations.  Be respectful, and if your ordered to something that you cannot do in good conscience, explain to your boss why you cannot do it.  He may throw a temper tantrum, but deep respect your commitment, and that will be the end of it.  On the other hand, it is possible that he will either fire you or start looking for a way to get rid of you.  If you suffer, because you will not compromise your Christian testimony, you will be in very good company.  Just read the Bible, and you’ll see that it’s not at all uncommon.