Thank you for that video, I would have posted that myself but I don't know how. What she talks about is the core of the the book which states
"Nothing real can be threatened, nothing unreal exists, herein lies the Peace of God."

In a nutshell she is talking about distinguishing between the world our ego created which is centered around "whats in it for me" (the world of illusions, degrees of sin and dichotomy) as opposed to God's reality, the loving thought behind creation which is we are all one in Truth and should love each other as ourselves. The ego created the idea of "sin" as we know it today. The term originally came from Aramaic which means "to miss the mark" (an archery term) or to miss the point. The ego believes in sin, death, pain and suffering and needs these things so that your true Self will believe in the ego rather than God. ACIM also teaches that there is nothing outside of yourSelf, but remember, its definition of the Self includes all your brothers and sisters and everything you see as One but it needs Atonement.

I admit I still struggle with this stuff sometimes. I let others upset me and I still sometimes get fearful and angry, but a lot lot less than I used to. This is normal of course. Its a journey, not yet at the destination which is no fear, only love. Peace to you, MH