Conscience as our Guide

Every person has a degree of moral understanding. It is what C.S. Lewis in his book Mere Christianity calls 'The Law of Human Nature' or the Law of Decent Behavior. It is an agreed upon law of right and wrong that is true of every civilization, culture, or society. God has written on the tablets of human hearts His law. But God has also given to every man a conscience, that inner voice that holds us to the standard. But is our conscience a good guide? Can we live solely by our conscience? The Book of Genesis reveals that some passed the test and lived godly lives ruled by their consciences. But many failed beginning with Cain who murdered his brother Abel. And over time, the entire human race failed to follow the dictates of their conscience which resulted in God's judgment through a universal flood. Only one family, Noah's, found grace in the eyes of the Lord. But is our conscience a good guide for today? It depends on the condition of our conscience for it can be corrupted or even seared. Most struggle with a guilty conscience. So how can we have a clean conscience that is void of offense before God and man?