A profoundly important message from an author I trust completely
This is the sixth book from Nancy Clark.  It's her most ambitious yet and in my opinion it represents a significant departure from her prior works.  This is because its subject, the unitive experience, is something that is difficult for a non-experiencer such as myself to understand.  I had never heard the phrase "unitive experience" before; as far as I know, it hasn't been discussed very much in the spiritually transformative experience literature.  This review will attempt to explain what the unitive experience is; why I believe this author is honest; and my interpretation of the author's advice about striving towards such an experience in our own lives.
Although I think I have a partial conceptual understanding of the unitive experience, it's clear to me that my understanding is rudimentary at best.  Although Ms. Clark does a yeoman's job in her description, she acknowledges that such a phenomenon can be understood only through direct experience.  She states that trying to describe it is like trying to describe color to a blind person.  However, that doesn't necessarily mean that we can't get a rough idea of what this experience involves and what it may mean.
If the following description sounds uncertain it's because I'm uncertain of the following description, but I'll try to describe my tentative understanding of the unitive experience.  The main and defining feature appears to be the loss of ego, or the loss of self during union with God.  The self is now nonexistent and only God and God's perspective remain.  I had tried to conceptualize this as the self being like a drop of water and God being like an (infinite) Ocean.  I was surprised to read that that's wrong.  Nancy Clark writes, "It is not blending into the ocean , the cosmos, everyone on the planet but merging into and seeing from God's vision or understanding." 
That sounds like some pretty heavy stuff to me.  But this is an author I trust, and I trust her for several reasons.  First, she's acutely aware of potential for appearing to be what she calls a "spiritual narcissist" for making the claims that she makes, but she also says this: "I want to be very clear, I was not a saint before my unitive experience nor did I become a saint afterwards."  Second, she has made statements that would be incongruent with those of someone who was telling false stories to get attention.  For example, in her first book, Hear His Voice, she noted that when driving, she would sometimes mourn tire treads on the highway because at first she thought they were dead animals due to her poor vision.  She also stated that her own family didn't believe her accounts, and that the hospital chart made no mention of the circumstances of her near death experience during childbirth.  These aren't the kind of self-effacing disclosures that would be made by a dishonest narcissist.  In fact, she makes it clear that she's actually quite uncomfortable writing about these things.  She'd have preferred to have kept all of her experiences to herself, but was asked by God to spread the messages.   Third, when I contacted her by email several years ago to ask questions,  she responded at length and in great detail over and over again.  She did this even though, as I later learned, her husband was diabetic, in renal failure on dialysis, and terminally ill.  She's done this for other people as well.  So yes, I believe her.
So how is the spiritual seeker to proceed?  Nancy Clark offers some valuable advice. First of all, a unitive experience can't be earned--it is granted by grace alone.  However, it is up to each and every one of us to put ourselves on the right path, "a path of deliberately choosing to turn your attention within to the living God until it becomes habitual."  My understanding is that we are called to live from a position of love, and to think and act accordingly; our soul's purity can increase in exact proportion to our loss of self.
This book is not an easy read, and the author makes it clear that the path toward transformation is not easy.  If you're looking for New Age fluff and feel-good platitudes, you won't find them in this book (or in any of her others).  If, on the other hand, you're looking for precious spiritual advice from a trustworthy and credible source, then you'll have found it in this book.  I give it my very highest recommendation.
W. Hoover, MD