Short answer: A sin is a real violation of God’s laws, a real attack that causes real harm and thus calls for punishment. An error is an imagined violation of God’s laws, an illusory attack that causes no real harm and thus calls for forgiveness. According to the Course, it is impossible to really violate God’s laws, and so there is no sin—all of our seeming sins are only errors.
A sin is a real violation of God’s laws, a real attack that causes real harm and thus calls for punishment.
Probably the Course’s best discussion of the difference between sin and error is the Text section entitled “Sin versus Error” (T-19.II), a section I recommend reading in its entirety. This section gives us one of the Course’s best definitions of sin:
To sin would be to violate reality, and to succeed. Sin is the proclamation that attack is real and guilt is justified. (T-19.II.2:2-3)
The key point this definition makes is that what makes a violation a sin is the reality of that violation—the attempted attack has to be successful. This makes perfect sense, does it not? For something to be a sin, someone or something must really be hurt by it. If no harm is done, there is no sin. (I realize that in some spiritual traditions the intent to harm is considered a sin even if no actual harm is done. However, as will become apparent below, the Course would clearly put the intent to harm in the “error” category.)
A perfect way to illustrate the idea that real harm must be done in order for a violation to be a sin is to use the example of dreams. If I were to have a dream in which I killed my wife, would this considered be a real crime, an actual sin? Unless I lived in one of those aboriginal cultures that sees dreams as more real than the waking state, of course not. I would simply wake up, see that my wife was still alive and well, and say, “Thank God it was only a dream!” In reality, no harm was done. Since no harm was done, I would have nothing to feel guilty about, and no reason to expect punishment.
But if I were to kill my wife in the waking world—the world we normally consider to be real—the situation would be quite different. In this case, because real harm was done (according to our conventional definition of “real”), I would undoubtedly feel guilty on some level, and if caught and convicted, I would undoubtedly suffer the punishment society reserves for cold-blooded murderers. In religious terms, my act would be a sin, and so my guilt and punishment would be quite justified.
This, of course, is the traditional biblical definition of sin: a real violation of God’s laws (like the law against murder), which God must punish because He is a God of justice. And while there are schools of thought that see the word “sin” in the Bible as referring to illusory error (Christian Science, for example), for the most part the reality of sin is a pillar of biblical religion. Certainly it is a pillar of traditional Christianity. One of the central beliefs of many Christians is the belief that Jesus atoned for our sins by dying on the cross, taking God’s just punishment for our sins onto himself. As reassuring as this belief is to many, it certainly affirms the reality of sin. We may be off the hook, but someone had to pay for our sins. Our sins must be awfully real if God had to punish His own Son in our place in order to save us from them.
Interestingly enough, the Course actually agrees that real violations of God’s laws really do deserve punishment: “If sin is real, then punishment is just and cannot be escaped” (W-pI.101.2:1). Fortunately, the Course also says emphatically that there is no such thing as a real violation of God’s laws. There are no sins, but only errors, which leads us directly to the Course’s definition of the term “error.”
An error is an imagined violation of God’s laws, an illusory attack that causes no real harm and thus calls for forgiveness.
The Course is adamant that it is truly impossible to violate God’s laws. Try as we might, we cannot successfully violate reality. We certainly believe we can (and believe we have), but this belief is nothing more than an error, one that the Course takes great pains to correct:
The Son of God can be mistaken; he can deceive himself; he can even turn the power of his mind against himself. But he cannot sin. There is nothing he can do that would really change his reality in any way, nor make him really guilty. (T-19.II.3:1-3)
All of our seeming attacks—including the ultimate attack, the attack on God that brought about the separation—have caused no real harm to anyone or anything, so they are simply meaningless errors rather than terrible sins. Now, this is certainly not how it seems to us. As we look around the world, it appears that attack in various forms has been harmful indeed, bringing very real pain and suffering to countless living things. How can it be, then, that our attacks are harmless?
The answer to this question is that no harm has really been done because all of the things that seem to be harmed are illusions, simply figures in a dream. In the above example, I contrasted the illusory world of dreams with the “real” world we see when we are awake. But in the Course’s view, the world we see when we are awake is just as much a dream as the world we see when we are asleep: “Your sleeping and your waking dreams have different forms, and that is all” (T-18.II.5:13).
Thus the harm we seem to do in this world is in fact no different than the harm we seem to do in our sleeping dreams. It is equally unreal, it has no effect whatsoever on reality, and so no sin has been committed. We have nothing to feel guilty about. God is a God of justice, and this fact now ensures that we will not be punished, because we did nothing deserving punishment (see T-25.VIII.8:1-2). (Obviously, this also means that we have no need for Jesus to be punished in our place.) Simply by shifting the status of our attacks from real to illusory, from sin to error, all of the painful effects that flow from the belief in sin are entirely undone.
I hasten to add that though our apparent attacks are not sins, they are errors that do have devastating effects within the dream of this world. Therefore, the Course does not take our errors lightly. On the contrary, it tells us that the error of listening to the ego and thus delaying our return to God “is tragic in time” (T-5.VI.1:3). It emphasizes that our mistaken choice for separation has “destructive results” (T-5.V.8:2) within the illusion, and elsewhere says that this choice is “powerful, active, destructive and clearly in opposition to God” (T-3.VII.5:2). Our errors are obviously no trifling matter in the Course’s view; they may not affect reality, but they certainly affect our experience of reality. And the Course stresses that in order to undo the destructive effects of our errors, it is crucial that we look straight at those errors and see them as they really are: “What is important is…the recognition of a mistake as a mistake” (M-7.5:8).
But while it is crucial that we recognize our errors and their destructive effects in this world, it is equally crucial that we recognize the ultimate unreality of those errors and their effects. What the Course says about fear thoughts early in the Workbook applies equally to all of our errors: We must learn to see them “as equally destructive, but equally unreal” (W-pI.16.3:3). Seeing both their destructive nature and their unreality is what leads to the correction of our errors through forgiveness. Seeing the destructive nature of our errors gives us the motivation we need to allow them to be corrected by the Holy Spirit; seeing the unreality of our errors is the way they are corrected, for it is the very essence of forgiveness. Forgiveness by definition is the recognition that what looks like real sin is simply unreal error, and so whatever errors we have made, we remain sinless Sons of God. As the Workbook says, “[Forgiveness] sees there was no sin. And in that view are all your sins forgiven” (W-pII.1.1:3-4).
We’ve seen that the difference between a sin and an error is that a sin is a real attack that does real harm, while an error is an illusory attack that does no real harm. And the choice of whether to see attack as a sin or as an error is entirely up to us. Moreover, our choice depends entirely on what we want to see. Do we want to see attack as a sin, an unforgivable violation of God’s laws that brings inescapable punishment upon us? Or do we want to see it as “nothing more than a mistake, entirely correctable, and so easily escaped from that its whole correction is like walking through a mist into the sun” (T-19.II.8:1)? Surely the choice is obvious. With the Holy Spirit’s help, we can make the choice to replace sin with error, and in so doing open the door for Him to replace attack with healing, punishment with forgiveness, and condemnation with love.