This is the most profound book that I have ever read. It cannot be verified empirically, only intuitively.
I have read many spiritual books over many years. For the same reasons as most people: to find love and to be free of pain. ACIM teaches that the essence of both is peace of mind. That fear and love cannot co-exist, and that one must, therefore give up guilt, which is the tool of the ego, by forgiving oneself. Forgiveness is not a mere intellectual exercise but a full, fundamental 'letting go' of the causes of pain - the things which cause us grief; the blame for what we feel we lack. Letting go of everything that causes pain.
Love is unconditional - it lets go because it's nature is to be free, not restrictive. The 'special' relationships we engage in and call 'love' falter because of the false premise on which they are based: Ego relationships are all conditional. To appreciate love we must invest in it by giving it to others and to life. The ego confuses possessiveness and love - it gives in order to get - appreciation, satisfaction, approval promoting the illusion that this can enhance our self-esteem or self-worth. The ego also incessantly recycles guilt and blame. Love is not something we must deserve or earn, but what we are. Forgiveness - letting go of pain, blame and guilt - is key to rediscovering our true selves.
This book will not change our life - only you can. But it may help you to focus on your own peace of mind as the peace of God, to acknowledge your true self as the son/daughter of God, and to express the loving greatness of your true self, rather than the limitations of a possessive ego. This books is not a one-time read or a 'quick-fix' but a life practice.
... When you are ready to discover who you truly are.