Among the many things all people should possess a good conscience should be paramount. If you have a good conscience then take time to praise God for it is a witness to the relationship between you and He.
The glory of a good person is the testimony of a good conscience. A good conscience is able to bear very much and is very cheerful in adversities. An evil conscience is always fearful and unquiet. Never rejoice except when you have done well. You shall rest sweetly if your heart does not accuse you. Sinners never have true joy or feel inward peace, because ‘there is no peace for the wicked,’ says the Lord (Isaiah 57:21). The glory of the good is in their consciences, and not in the tongues of others, The gladness of the just is of God, and in God; and their joy is of the truth.
A person will easily be content and pacified whose conscience is pure. If you consider what you are within, you will not care what others say concerning you. People consider the deeds, but God weighs the intentions. To be always doing well and to esteem little of one’s self is the sign of a humble soul. For not he who commends himself is approved, but whom the Lord commends, ‘says Paul (2 Corinthians 10:18). To walk inwardly with God, and not to be kept abroad by any outward affection, is the state of a spiritual person. Conscience is that faculty in me which attaches itself to the highest that I know, and tells me what the highest I know demands that I do. It is the eye of the soul which looks out either toward God or toward what it regards as the highest authority. If I am in the habit of steadily facing toward God, my conscience will always introduce God’s perfect law and indicate what I should do. The point is, will I obey? I have to make an effort to keep my conscience so sensitive that I walk without offense. I should be living in such perfect sympathy with God’s Son that in every circumstance the spirit of my mind is renewed. The one thing that keeps the conscience sensitive to Him is the habit of being open to God on the inside. When there is any debate, quit. There is no debate possible when conscience speaks.
C.F.H. Henry, Christian Personal Ethics, Eerdmans, 1957, p. 509ff