Individuals sometimes use the word “conscience” to define or defend what they do. For the most part conscience as used in scriptures refers to the way one was raised. The thought being that each person would not violate their conscience. God used the conscience of the Gentiles to judge them apart from the law of Moses (Rom. 2:15). The same verse points out if they did the work of the law written in their hearts. The two times Abraham lied about Sarah being his wife, Abimelech and Pharaoh both condemned what Abraham did. Pharaoh in Genesis 12 and Abimelech in Genesis 20. This was before there was ever the “ten commandments”.
Paul told his audience in defense in Acts that he had lived in accord with his conscience all his life (Acts 23:1). When Stephen was put to death in Acts 7, Paul was in agreement. Later he was placing Christians in prison and in some cases, Christians were put to death. When this happened Paul would later tell Agrippa, that he was in agreement with those actions (Acts 26:10,11). He did not violate his conscience although he was guilty of participating in punishing Christians and in some cases seeing them put to death. Later he would write that in his zeal he persecuted the church (Phil. 3:6).
A person may be raised wrong by sincere people who believe they are right. Sincerity is not the question, neither is feeling good the answer. Only the conscience that is trained by being in the Word of God can be a safe guide. Otherwise we trust ourselves and we all know too well that danger as in the case of Jacob believing that Joseph had been killed by some animal. We should all engage in a constant study of scripture to be sure that what we have been taught is from God and not man.