A conscience forms in us on the basis of whatever religious tradition we follow, depending on how deeply we internalize that tradition.
For people in the [Christian] church, their conscience is shaped either by truths [they themselves have drawn] from the Word that have become part of their faith or else by things based on the Word that they have been taught by others, depending on the extent to which they have taken these to heart. As we come to know and believe truths and comprehend them in our own way, when we will them and do them, then our conscience comes into being. Taking them to heart is taking them into our will, because our will is what we refer to as our heart.
That is why people who have a conscience say from the heart whatever they say, and do from the heart whatever they do. They also have a mind that is not divided, because what they do is consistent with what they understand and believe to be true and good.
People who are more enlightened than others concerning the truths of their faith, and who are more perceptive than others, are equipped to have a better conscience than people who are less enlightened and are less perceptive.
A genuinely spiritual life is a matter of having a true conscience, because in it our faith is joined to our caring. In that case, we see following our conscience as following the principles of our spiritual life, and going against our conscience as going against the principles of our spiritual life. As a result, when we act in accord with our conscience we feel calm and peaceful and have an inner sense of well-being, but when we go against our conscience we feel disturbed and pained. This pain is what people refer to as “pangs of conscience.”
People can have a conscience that is focused on what is good, and they can have a conscience that is focused on what is right. A conscience that is focused on what is good is a conscience that resides in our inner self; a conscience that is focused on what is right is a conscience that resides in our outer self. If we are driven from within to live by the precepts of faith, we have a conscience that is focused on what is good; if we are driven by outward considerations to live by civil and moral laws, we have a conscience that is focused on what is right. People who have a conscience that is focused on what is good also have a conscience that is focused on what is right.
People who have only a conscience that is focused on what is right nevertheless have the capacity to develop a conscience that is focused on what is good, and they do so when they are taught about it.
The type of conscience that is found in people whose lives are devoted to caring about their neighbor is a conscience focused on truth, because it is formed through the faith they have in the truth. The type of conscience that is found in people whose lives are devoted to love for the Lord, though, is a conscience focused on goodness, because it is formed through the love they have for the truth. The conscience the latter people have is of a higher kind and is called a perception of the truth that arises from goodness.
People who have a conscience focused on truth are part of the Lord’s spiritual kingdom; people who have the higher conscience, the one called perception, are part of the Lord’s heavenly kingdom.
Some examples may help to show what conscience is. Suppose you have another’s goods without the other knowing it and can therefore profit from them with no fear of the law or of loss of position or reputation. If you nevertheless return the goods to the other because the goods are not yours, you are someone who has a conscience; you are doing a good thing because it is good, and doing the right thing because it is right. Or suppose you are offered a government position but you know that someone else who also wants that position would be of greater benefit to your country than you would. If you let the other person have the position for the good of your country, you are someone who has a good conscience. A similar principle would apply in many other situations.
On this basis we can tell what people who have no conscience are like; we can identify them because they are the opposite. For example, if for the sake of profit they make something that is wrong look right or something that is evil seem good (or the reverse), they are people who have no conscience. They do not even know what conscience is, and if someone tells them what it is they do not believe it and some of them have no interest whatever in learning more.
That is what people are like who do everything for worldly and selfish reasons.
If we do not develop a conscience in this world we cannot develop one in the other life and therefore we cannot be saved. This is because in that case we do not have a level into which heaven can flow and through which it can work—that is, a way in which the Lord can act by means of heaven to lead us to himself. This is because our conscience is the level within us into which heaven flows; it serves as the part of us that receives heaven’s inflow.
from New Jerusalem, Sections 130-138