In what situations does the Bible say it's acceptable, perhaps, to do an action you might consider sinful? Generally speaking, the bible is very clear that:


Authority is set up by God.
If this authority, eg, a the governing heirachy, is in conflict with God (as was the case in the book of Daniel), then it is to God that we must submit to, not to man.


However, I seem to remember one place where a man's actions, which would have been sinful if he had any choice in the matter, were regarded as acceptable behaviour because he performed them without free will in obedience to his king.

Sadly I can't remember if this was something as trivial as being cup bearer, where one consumes potentially poisoned drinks at risk of great personal harm, or if there was a more significant event.

Could someone tell me of any such situations?  This is relevant today if, eg, in the army you are commanded to kill someone, and for some reason you believe that, in that particular case, it might be murder.  Where does the bible stand on such grey situations?

(Note:  I am not talking about clear situations - some readers here will adopt a hardline answer, to the point where a solder should not kill anyone in the course of battle. That is fine, those readers have a clear answer.  I am asking about what to do when the situation is NOT clear, perhaps due to insufficient information, insufficient knowledge, or simple lack of free will).
The situation you are probably thinking of is Naaman, whose story appears in 2 Kings chapter 5. Naaman, 'commander of the army of the king of Aram', was healed of leprosy through the prophet Elisha, and becomes a follower of God. He says:


  Your servant will never again make burnt offerings and sacrifices to any other god but the Lord. But may the Lord forgive your servant for this one thing: When my master enters the temple of Rimmon to bow down and he is leaning on my arm and I have to bow there also—when I bow down in the temple of Rimmon, may the Lord forgive your servant for this.” (verse 17-18)


On the other hand, if you read the story of Daniel, he and his companions Shadrach, Mesdhach and Abednego refused to follow the commands of the King and were thrown into a den of lions/fiery furnace for this. So you can't take this as a universal example.

You might also like to read Matthew Chapter 12, where Jesus gives a couple of examples of doing things that were not lawful - especially David, who ate the forbidden bread when he and his companions were hungry.