Editor's Note: Shannon Ethridge is an advocate for spiritual and sexual integrity. She is a counselor, speaker, author and certified life and relationship coach. Her 19 books include the million-selling Every Woman's Battle book series, "The Sexually Confident Wife" and her latest book, "The Fantasy Fallacy," a response to the "Fifty Shades of Grey" phenomenon, a discussion of the roots and role of sexual fantasies.

By Shannon Ethridge, Special to CNN

(CNN) - When a friend alerted me to the "Fifty Shades" trilogy in April, none of us had any idea it would sell in excess of 40 million copies within months, or that sales of whips, chains and other BDSM paraphernalia would skyrocket as a result, or that a European hotel would replace its Gideon’s Bibles with "Fifty Shades of Grey."

Many legitimate possibilities have been offered for the seeming success of “mommy porn.” Women are more sexually liberated than ever before. Couples are longing for ways to spice up their sex lives. Many women have a deep inner longing to be dominated by a man who’s absolutely obsessed with them.

While there might be some truth to each of these theories, I think the real force behind this "Fifty Shades" phenomenon is that our society is clamoring for closeness. However, in the absence of genuine sexual intimacy (best defined as “in-to-me-see”), we settle for sexual intensity: erotica, pornography, an office romance, an extramarital affair or whatever strokes the ego and provides the sexual high we crave.

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I suggest that sexual intensity (such as that experienced between the lead characters of the "Fifty Shades" trilogy) is simply not the same as intimacy. If it were, then prostitutes and porn stars would be the most emotionally and relationally fulfilled people on the planet. That doesn’t seem to be the case.

Does the entangling of arms and legs and the exchange of bodily fluids scratch the human itch for intimate connection? Or is sex just the closest thing we can imagine to what we’re really craving: a deeper spiritual and emotional connection, both with our Creator and with His creation?

When I explain through my writing, speaking and life coaching that I am an “advocate for healthy sexuality and spirituality,” some assume I’m insane. Why would someone even use the terms “sexuality” and “spirituality” in the same sentence? I do so because I believe they are basically the same thing, or at least two sides of the same coin.

Regardless of gender, age, race, political views, economic status, etc., all humans have two things in common: We are both spiritual and sexual beings. And behind every sexual longing, I believe there’s an even deeper spiritual longing.

So we have much to learn about God through understanding our sexuality, and there is much to learn about our sexuality through a deeper exploration of God.

Looking at sexuality through a spiritual lens, and vice versa, is not a new concept. In the Song of Solomon, a man's and woman’s desires for healthy sexual intimacy are celebrated. In the book of Hosea, God uses the analogy of a husband’s relentless pursuit of a sexually unfaithful bride to illustrate the depth of His own passion and commitment to His people. God obviously knew that “sexual metaphors” would teach us about ourselves and about Him.

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This brings me back around to the "Fifty Shades of Grey" phenomenon. I don’t believe that fantasy is evil, even sexual fantasy. But when we divorce physical pleasure from emotional connection, such as when we selfishly strive for orgasm through pornography, masturbation or illicit sexual encounters rather than cultivating sexual ecstasy with our marriage partner, sexual ecstasy is only “half-baked.” Love and relational intimacy are the “yeast” that allows our sexual ecstasy to rise to its highest level.

My counseling experience shows me that we often seek healing for our deepest wounds via sexual encounters. Our minds and hearts believe we will “get it right” or “find the love I need” via an intensely satisfying sexual relationship.

If deep and spiritual intimacy is what humans seek, then relational or sexual intensity can never satisfy our deepest longings or heal our oldest wounds. Christian and Anastasia (for all the "Fifty Shades" fans) won’t discover heart-deep intimacy in whips, chains, pain and sexual intensity. Their deep wounds will be healed by sacrificial love (of which Christ is the incarnate example) and intimate relationship (both human and divine). Soul-deep intimacy is what we seek, and it’s ultimately found in the God who created human sexuality.

The opinions expressed in this commentary are solely those of Shannon Ethridge.