Cling to your faith in Christ, and keep your conscience clear. For some people have deliberately violated their consciences; as a result, their faith has been shipwrecked. (I Timothy 1:19)
The conscience is made up of what we refer to as morals and principles - amassed while growing up. They act to define the actions we will allow in our lives and those we will reject because they don't align with this learned set of morals and principles. Whenever we are asked to violate our conscience, we might just feel a little anxious, fearful, or even guilty. In the strictest sense, the conscience has a "prohibiting" effect - if the conscience becomes a little "dulled" with the wrong set of morals or principles being applied, it may guide us into some pretty awkward circumstances. This is why we don't trust our conscience alone - it is only ONE tool used in the myriad of tools God gives us for our spiritual, emotional, and physical safety. Keep your conscience clear - the instruction is to not deliberately violate it. The smallest compromises in either our morals or principles can lead to the bigger ones. Our inward motivations dictate our outward actions - think about it long enough and you will act upon the thought! The other guiding influences in life are the Word of God, his Holy Spirit residing in us, and the sound teaching of godly people. Violate ALL of these and the road will be a really rocky one!
Conscience requires discipline - in order to form the right set of morals by which we make what people refer to as judgment calls. If your morals haven't been the best as you were growing up, or because you made compromises later on in life, there is still hope. Morals are just the "rules" of conduct by which we live - if you put Christ in charge of defining these, you will actually see them begin to change! You may have been raised in a home where criticism and nit-picking were just the "norm". In the community of believers where you now associate, this may not be considered very loving or kind. When we submit these "learned traits" to God, he goes about helping us "unlearn" them. Trust me, I know for a fact the things we have to "unlearn" are way harder than the ones we have to "learn"! We begin to realize the "changing of the guard" in our conscience whenever we begin to see the wrong choice before we make it, realizing it as a wrong choice. This is a good first step - learning to heed it is another! Conscience is "situational" at times - we go with it when it is the easiest choice, but we sometimes don't heed it when it is the toughest! How is it we get our conscience to not sell us short? I think it comes by keeping our eye on the three indicators of "right" or "wrong" in our lives - God's Word (what does it have to say about what it is we are about to do); God's Spirit (when is he giving us that internal "niggling" to respond or deny the response); and lastly, our conscience. I put conscience last because it is the least reliable source, so it doesn't deserve placement over God's Word or his Spirit!
Conscience can help us recognize sin in our lives - but not always stop us from engaging in sin. We need the other sources of "recognition", as well. Once we recognize sin has a foothold in our lives, there is but one response which is correct - turn away from it. This is what we call repentance. The most important thing if we want a change of conscience is the "changing of the guard" - determining who will be the center of our focus and choices. If it remains us, we will fail repeatedly because our conscience will not always protect us. If we choose to make Christ central in our world, the changing of the guard over our minds and choices becomes a reality! What does this look like? Perhaps it is learning to take a little time before we respond - just so we can be sure we are responding to the "right" voice. Maybe it is taking time to think about what we have learned from scripture - the "what does God say" principle. No guard is worth their weight in gold unless that guard actually preserves, protects, and pursues what is right. Just sayin!