Short answer: Unconditional love is the Love of God, the only real Love: a limitless, changeless Love that embraces everyone and does not have to be earned in any way. We are forever worthy of unconditional love, because God created us as beings who are both lovable and loving, and our true nature cannot be changed. We can restore our awareness of God's unconditional Love and of our own true, loving nature by meeting the conditions necessary for this restoration; in particular, by loving our brothers unconditionally through forgiveness.
Unconditional love is the Love of God, the only real Love: a limitless, changeless Love that embraces everyone and does not have to be earned in any way.
"Unconditional love"—love that is given freely and without reservation to everyone, whether it seems to be "deserved" or not—is an attractive ideal for many of us. I remember singing the Donna Summer song "Unconditional Love" in the church I used to attend, a song whose chorus goes like this:
Give me your unconditional love.
The kind of love I deserve.
The kind I want to return.
But however much we may be attracted to unconditional love in theory, in practice I think most of what we call love is of the conditional variety. As a general rule, we don't give our love to just anyone; instead, we have standards (conditions) that must be met before we will consent to bestow such a precious gift. The particular standards we use are many and varied. We may choose to love certain people because they are part of our family, because their personalities are compatible with ours, because they share our political or religious views, because they are decent and moral people in our eyes, because they say and do the things we want them to say and do, because their bodies are attractive (a big factor, however unwilling we are to admit it), or for a host of other reasons. But whatever the particular standards we use, the upshot is that we give our love to those who meet our conditions, and withhold it from those who don't. And once we find someone who meets our conditions, he had better stay on his toes if he wants to keep receiving our love. If he stops meeting our conditions (or if our conditions change and he doesn't change with them), he will bask in the sunshine of our love no longer.
Thus, what we call love is a pretty limited and fickle beast. It is limited to certain people in certain situations, and can change instantly to hate (or indifference, which is really just another form of hate) if those people, situations, or even our own standards change. It is not a free gift bestowed on everyone, but is given only to certain people for a price; the selected "loved" ones must earn it by meeting our conditions, and hold onto it by continuing to meet our conditions.
But according to the Course, this conditional "love" is not love at all, but merely a pallid imitation of love, the ego's hate masquerading in a "loving" form. As such, it is completely foreign to love's true nature. In the Course's view, "there is no love but God's" (W-pI.127.Heading), and God's Love is totally unconditional. (The Course never actually uses the phrase "unconditional love," but it definitely expresses the concept.) Thus, unconditional love is not just a particularly exalted or ideal form of love, the pinnacle of a continuum that includes many lesser forms. Instead, unconditional love is the only kind of love there is. "Unconditional" is part of the very definition of love; unconditional love is the only thing that truly deserves to be called "love." The following passage gives us some idea of the true nature of love as the Course sees it:
Love is one. It has no separate parts and no degrees; no kinds nor levels, no divergencies and no distinctions. It is like itself, unchanged throughout. It never alters with a person or a circumstance. It is the Heart of God, and also of His Son. (W-pI.127.1:3-7)
The true nature of love is thus the antithesis of love as we usually understand it. God's Love, the wellspring of all true love, is not limited to certain people and situations by the conditions we have established; by definition, it is unlimited. God's Love is not a fickle beast that changes with every shift in the wind; by definition, it is changeless. As the Course says, "What can change was never love" (T-16.IV.4:4). The upshot of this is that love, by definition, does not have to be earned by meeting conditions: "Being complete, it asks nothing" (T-15.VII.1:4). Rather than a rare commodity doled out to a select group of people who have paid the price for it, the true Love that emanates from God embraces His entire creation and costs nothing at all. It is a totally unconditional, universal gift: "All His children have His total Love, and all His gifts are freely given to everyone alike" (T-1.V.3:3).
We are forever worthy of unconditional love, because God created us as beings who are both lovable and loving, and our true nature cannot be changed.
Unconditional love is simply part of our true nature, since our nature is an extension of God's nature: "God is but love, and therefore so am I" (W-pI.rV.In.4:3). Yet much of the time, we don't feel either very lovable or very loving; whatever Donna Summer's song may say, we often don't think unconditional love is the kind of love we deserve, nor are we too eager to give it to people we think are at least as undeserving as we are. If unconditional love is part of our nature, why then do we generally feel so unworthy of such love, and so loathe to offer it?
In the Course's view, we feel this way because, deep down, we believe we have changed our nature, and therefore are no longer lovable or loving. The ego has convinced us that God's Love does indeed have conditions, and that we violated those conditions big time when we decided to separate from Him. In this act of rebellion, we rejected His Love and thus changed our very nature from loving Sons to hateful sinners. As long as we believe that our nature has been so utterly and permanently defiled, we cannot love ourselves, and we certainly cannot love our brothers, who are just as wretched as we are. Nor can we love God, Who must now become the punisher of our sins. Our rejection of God and the nature He gave us places us forever beyond the pale of His Love, forever unworthy of anything but His contempt, worthy only of everlasting damnation.
But the good news is that whatever the ego may tell us, our true nature is unchangeable. As the Course never tires of reminding us, the separation is nothing but an illusion, and we remain as God created us. We may see ourselves as the work of the devil, but we "are the work of God, and His work is wholly lovable and wholly loving" (T-1.III.2:3). We can believe we have altered our nature and we can weave intricate illusions to convince ourselves that this has been accomplished, but the fact remains that "nothing [we] can do can change Eternal Love" (C-5.6:10). Thus, we have every reason to love ourselves, our brothers, and God without reservation. All of us are forever worthy of unconditional love, because God created us worthy, and that can never change. We do deserve unconditional love, and we do want to return it. In God's eyes, we are "forever loving and forever loved" (W-pII.10.5:1), and this is the way we must see ourselves and everyone if we are to remember who we really are.
We can restore our awareness of God's unconditional Love and of our own true, loving nature by meeting the conditions necessary for this restoration; in particular, by loving our brothers unconditionally through forgiveness.
Even though love itself is always unconditional, the Course does speak of various "conditions" that we must meet in order to restore our awareness of God's Love (in other words, to awaken to Heaven). These conditions are not the kind of conditions that we normally establish as the price that must be paid for love; this is "not a bargain made by God, Who makes no bargains" (T-8.I.1:5). Rather, these conditions have become necessary because we have willfully pushed awareness of our true, loving nature out of our minds. God cannot restore that awareness against our will, because this would violate our freedom of will, which is part of our true nature. Therefore, there are things we must do on our end—conditions we must meet, conditions that are expressions of our willingness to return our minds to God—in order to become fully aware of God's unconditional Love once again.
What are these conditions? In general terms, they are all mental states the Course wants us to cultivate and ultimately attain. Specifically, some of the conditions the Course says are necessary for the restoration of our minds to God include peace (T-8.I.1:3), total harmlessness (T-8.IX.2:2-3), willingness to accept God's gifts (T-4.III.5:3-5), the recognition that God's Son is guiltless (T-14.IV.7:4), the relinquishment of judgment (M-9.2:7), and forgiveness (M-20.3:6). All of these conditions are simply different ways of referring to the Course's goal of true perception, the one prerequisite for awakening to the knowledge of Heaven. So, the essential condition we must meet to be restored to the "condition of the Kingdom" (T-8.I.1:3)—the Heavenly state in which we know God's Love—is to perceive in a way that is an earthly reflection of the condition of the Kingdom. Perceiving truly on earth paves the way for knowing truth in Heaven.
What this boils down to is that it is through unconditionally loving our brothers on earth that we restore our awareness of the unconditional love of Heaven. "Teach only love, and learn that love is yours and you are love" (T-6.III.4:9). And since the love of Heaven in its pure form is beyond perception, unconditional love on earth takes the form of forgiveness, the "earthly form of love" (W-pI.186.14:2), the true perception of our brothers and ultimately ourselves. To awaken to love, then, we must forgive our brothers for not meeting all the conditions we have set up for them to earn our "love." We must also let go of the conditions themselves, and stop using them as a rationale to "love" some people and reject others. We must set aside our judgment of our brothers, a judgment that evaluates their worth and lovability on the basis of what their bodies look like, say, and do. We must withdraw our investment in what the body's eyes show us, and see our brothers instead with the eyes of the Holy Spirit, Who sees beyond their bodies to the truth in them. As we practice this over time, we will more and more come to see each brother as the loving being he truly is. "What is in him will shine so brightly in your grateful vision that you will merely love him and be glad" (T-20.V.4:4). Through forgiveness, we will learn at last how to love our brothers (and ourselves) unconditionally, just as our Father does.
Yet what does loving our brothers unconditionally mean in the rough and tumble of daily life? Does it mean that we must have no conditions or limits of any kind? Does it mean that we must never establish behavioral rules for our children, our sex life must be '60's style "free love," an abused spouse must mutely take whatever her abuser dishes out, all of the murderers must be released from prison, and we must do absolutely nothing to prevent further attacks from the terrorists who attacked America on September 11?
I don't think so. Unconditional love is a state of mind; it doesn't mandate any particular set of behaviors, though it will often be expressed behaviorally in some form. The Course says that the Holy Spirit is to be in charge of behavior, and if we listen to Him, He will guide us to express our unconditional love in a way that is most beneficial to all concerned. Given the practical necessities of life on earth, I think that in many cases the Holy Spirit undoubtedly guides us to set reasonable limits on behavior, such as those we set on children, sexual activity, spouse abusers, murderers, and terrorists. But even when we must set limits on behavior, we need not set limits on our love. The content of our minds can be total unconditional love, even when the form that love takes involves setting conditions on behavior. And the loving content of our minds is the crucial thing here. However it is expressed behaviorally, it is this loving state of mind that will restore us at last to full awareness of the Love of God, the Love that is our own true nature.
One of the things that has always struck me about the Course is the pure, total, and absolute nature of the Love that it sees at the heart of reality. Many if not most spiritual traditions agree with the Course that ultimate reality is essentially loving; however, at least from my point of view, in these other traditions there always seems to be a catch. One major catch for me is that however ultimate reality is conceived, it is almost always regarded as the Source of this painful physical world. Moreover, this Source always seems to be punishing us in some way if we don't meet its conditions, whether through the judgment and damnation of a personal God, or the harsh law of cause and effect that governs a more impersonal universe. It has always been very difficult for me to reconcile all of this pain and punishment with a reality that is truly loving.
That is one of the main reasons I was drawn to the Course. For in the Course, I find a love that has no catch whatsoever. I find a God Whose Love is absolutely perfect, so perfect that it is impossible that "His Love could harbor just a hint of hate" (T-29.I.1:5). I find a God Whose creation is not a painful physical world, but a limitless spiritual extension of His limitless Love. I find a God Whose Love is so pure and unconditional that even when it seems we have failed Him utterly, corrupted our nature beyond hope of redemption, and made ourselves deserving of eternal damnation, all He does is continue to love us. In the face of our apparent failure to meet the "conditions" we think He has established for His Love, all He does is gently reassure us that we remain His immortal beloved, and all we need do is open the floodgates of our hearts to the Love that has never left us:
"You are still My holy Son, forever innocent, forever loving and forever loved, as limitless as your Creator, and completely changeless and forever pure. Therefore awaken and return to Me. I am your Father and you are My Son." (W-pII.10.5:1-3)