131. A member of the church has his conscience formed by the truths of faith he learns from the Word, or by teaching from the Word, depending upon how he receives them in his heart. For when someone knows the truths of faith and grasps them in his own manner, and so comes to will and do them, then he develops a conscience. Receiving them in the heart means in the will, for a person's will is what is called the heart. That is why those who possess a conscience speak from the heart what they say, and do from the heart what they do. They also have their mind undivided, for they act in accordance with what they understand and believe to be true and good.