The men of David said to him, "Behold, this is the day of which the LORD said to you, 'Behold; I am about to give your enemy into your hand, and you shall do to him as it seems good to you.'"

Then David arose and cut off the edge of Saul's robe secretly.  It came about afterward that David's conscience bothered him because he had cut off the edge of Saul's robe.

So he said to his men, "Far be it from me because of the LORD that I should do this thing to my lord, the LORD'S anointed, to stretch out my hand against him, since he is the LORD'S anointed."
1 Samuel 24:4-6 

Paul, looking intently at the Council, said, "Brethren, I have lived my life with a perfectly good conscience before God up to this day." Acts 23:1  

In view of this, I also do my best to maintain always a blameless conscience both before God and before men. Acts 24:16  

Keeping faith and a good conscience, which some have rejected and suffered shipwreck in regard to their faith. 1Timothy 1:19  

For this finds favor, if for the sake of conscience toward God a person bears up under sorrows when suffering unjustly. 1 Peter 2:19  

Keep a good conscience so that in the thing in which you are slandered, those who revile your good behavior in Christ will be put to shame.
1 Peter 3:16