The ego is a state of insanity, in which what is true and false are completely confused with each other. In ego we have conditional love. We believe that some things are just downright evil, guilty, bad and wrong. We categorize the world into a hierarchy and we decide certain things like murder, war, sickness etc are all hell, while other things like sunsets and rainbows are lovable.
Unconditional love on the other hand would say that it loves ALL the time regardless. It sees innocence and harmlessness everywhere. Which means it continues feeling love even in the face of evil and war, attack and murder and death. It keeps smiling regardless. It even finds something beautiful to see in it.
To the ego it's going to have a reaction that this is completely insane. To suggest that war is not bad, and sickness is not wrong, and all forms of suffering are lovable. You'll feel like protesting against the idea of awakening because it flies in the face of everything the world believes. It goes against your moral compass and your sense of values and of what is good and evil.
Real love doesn't change when situations change, it doesn't adapt to the situation and it doesn't pay any attention to the form of what's happening. It could be considered oblivious and seemingly inconsiderate in a sense.
ACIM it telling us that we need to find a way to love the world even though, in and of itself, its own nature seems unlovable. Even the war and destruction and murder has to be somehow forgivable, and forgiveness is an earthly form of love. A form of unconditional love. But the idea of loving hell, or loving attackers, or loving abusers, or loving punishment, it all starts seeming outrageously blasphemous and offensive to the ego.
The ego in its insanity always believes that anything truly sane is insane. It thinks God is evil. It believes heaven is hell. It wants nothing to do with the truth or the Holy Spirit. Ideas of unconditional love are seen as treacherous and ignorant and lacking compassion for the "real suffering". Anything which really makes true sense is seen as completely nonsense.
This is why it can seem challenging to "wake up" because our egos actually believe the direction we need to head in is going to take us further into insanity, closer to evil, and away from safety. At first the notion that you can see beauty in something "the son of God made in hate" seems impossible and ridiculous. The idea that objects and forms of separation and attack could be regarded as representing the truth, seems completely false.
But somehow we still have to find a way to consider how it may be possible that there is a higher vantage point, capable of being forgiving towards attackers, capable of loving hell, and even capable of translating hell into heaven. The idea that earth can reflect heaven in spite of its completely flawed-seeming nature, at least on the level of form, seems far out of reach, and unwanted, but must be accomplished if we are to rise above the battlefield into the light.