Conscience is like a sundial. When the sun shines upon a sundial it points us to the right time. In the same way our consciences point us in the right direction in life. However, it’s important to remember that the sundial works only when the sun is shining upon it. When the moonlight shines on the dial it points to the wrong time. When a torch is shone upon the sundial it again points us to the wrong time. In these instances the sundial is unreliable. In the same way our consciences are sometimes unreliable because the “light” shining upon them is not the voice of God, but the voices of our families or our culture or even Satan. In these instances we’ll feel false guilt over things that should not make us feel guilty, or no guilt over things that should! The key for the Christian is to have their conscience continually illuminated by God’s Spirit.
Source: reported in John White, The Fight