In my “Marriage Makes Us Richer, Part 1” post, I linked to an article “ 10 Ways Getting Married will Make You Richer.” Of the ten ways mentioned in that article, cohabitants can participate in the first two ways, i.e. “1. Getting together and splitting the bills,” and “2. Combining the furnishings.” However, the other eight ways appear to be inaccessible to cohabitants. Research currently indicates that cohabitants do not appear to benefit nearly as much financially from their coupled living arrangement as do married couples. Why?
Sometime ago a leading scholar in the field of leadership studies, Warren Bennis, surprised me. He wrote a book, Leaders: The Strategies For Taking Charge, to describe a study of leadership he had conducted. This study consisted of ninety interviews with eminent national leaders; “sixty with successful CEOs, all corporate presidents or chairmen of boards, and thirty with outstanding leaders from the public sector.” .
Bennis interviewed men like “Harold Williams, former chairman of the Securities and Exchange Commission”, Ray Kroc of McDonald’s, and business leaders of Fortune 200 corporations such as ARCO, Times-Mirror, Inc., J.C. Penney, etc. The average income for the corporate CEOs was “$400,000 (without “perks”)” at that time, i.e. some time prior to 1985. Among the CEOs, Bennis discovered a surprise. He found that “almost all were married to their first spouse. And not only that: they were also indefatigably enthusiastic about marriage as an institution.” Other than that, he found no obvious demographic “patterns for their success.” 
Almost all were married to their first spouse
I repeat his words: “Almost all were married to their first spouse,” and they were “indefatigably enthusiastic about marriage as an institution.” Why were they so enthusiastic? In addition to the love that flows in a good marriage, perhaps their spouses were important to their accomplishments.
Thomas J. Stanley, Ph.D. Business Administration, a former university professor has been researching the wealthy in America since 1973. He, with William D. Danko, Ph.D., wrote the best seller, The Millionaire Next Door. In his book, The Millionaire Mind, he wrote:
Studies have consistently found a significant correlation between length of marriage and wealth accumulation. One study of over twelve thousand respondents is particularly illuminating, (Janet Wilmoth and Gregor Koso, “Does Marital History Matter? The Effect of Marital Status on Wealth Outcomes Among Pre-retirement Age Adults,” Proceedings of the 1997 North Central Sociological Association). The authors found that “consistent participation in marriage results in significantly higher wealth.” 
He further wrote that “divorce generally has a devastating impact on an individual’s net worth, and that’s true for both millionaires and nonmillionaires.” He said that “92 percent of the millionaire households in America are composed of a married couple, and these millionaire couples have less than one-third the divorce rate of nonmillionaire couples.”  Phil Thompson, a business lawyer created a nice summary of Thomas Stanley’s findings. See the article Millionaire Couples: The Unmistakable Link Between Marriage and Wealth.
I am not a millionaire, but I am “indefatigably enthusiastic about marriage as an institution.” I asked my wife Peggy, “Are you ‘indefatigably enthusiastic about marriage as an institution?’” She said yes. Marriage has helped me be much more productive. Our mutual commitment to each other has enabled us to sacrifice for one another and support one another on endeavors that have financially blessed our marriage and family. Our marriage has created a synergism.
Synergism is “the simultaneous action of separate agencies which, together, have greater total effect than the sum of their individual effects.”  Sometimes this definition is applied to the word synergy as well. Stephen R. Covey said, “Synergy is everywhere in nature. If you plant two plants close together, the roots commingle and improve the quality of the soil so that both plants will grow better than if they were separated. If you put two pieces of wood together, they will hold much more than the total weight held by each separately. The whole is greater than the sum of its parts. One plus one equals three or more.” 
These educational sacrifices, in which we mutually supported one another, resulted in dramatic increases in our household income. These were accomplishments that neither of us could have done alone.
I served as a sergeant in the Army when my wife and I married. When our children were very young, my wife raised our children and managed our home. Later, when I had left the Army and attended college, both my wife and I worked part-time to help me finish my bachelor's degree. When I attended graduate school, my wife and I continued this arrangement. Later, I would support my wife while she attended college and obtained her Registered Nurse license and later obtained a bachelor's degree in nursing. These educational sacrifices, in which we mutually supported one another, resulted in dramatic increases in our household income. These were accomplishments that neither of us could have done alone.
For example, when I later attended graduate school to obtain my school psychologist certificate, I experienced two significant panic attacks. The first lasted four days and because I could not eat, I lost six pounds. To relieve the stress, I felt compelled to write the graduate school and withdraw after I had been accepted. Because the school encouraged me to apply again later, I did, about a year-and-a-half later.
After my first class, I experienced another significant panic attack. This time my wife gave me tremendous emotional support that enabled me to continue classes. Without my wife's love and support, I would have dropped that class. Instead, I continued to attend, study and complete assignments until I succeeded.
I realize that not all marriages are synergistic, but as I observe my friends’ and neighbors’ happy marriages, I sense that most of these “happy marriages” are synergistic.
However, I also think that the couples in these “happy marriages” have worked hard, individually and together to improve their marriages. For example, I realize I chose my wife well, but both my wife and I have worked hard individually and together to improve our marriage; to make our marriage positively synergistic. We have experienced our share of suffering, but each of us has made adjustments within ourselves, within our souls, adjustments to our personal thoughts, feelings, and actions to make our marriage better.
If I have interpreted the research correctly, financially at least, cohabitation does not generally enable couples to reach this kind of synergism. It appears that cohabitating couples, by definition, do not make the commitment necessary to achieve this synergism. They can save money by sharing expenses, but their lack of a public, legal, and permanent commitment makes it risky to do the financial things married couples do.
They can, but they probably should not mix their finances the way married couples do. Why? The reason is that they are so much more likely to break up and they are so much more likely to break up quickly (compared with married couples).
Jeff Opdyke is a nationally syndicated writer whose column Love & Money has reached “ten million readers in more than 80 newspapers across the country.” He wrote for both married and unmarried couples in his book, Financially Ever After: The Couples Guide to Managing Money, and he said, “There are bad financial decisions, and then there are horrendously bad financial decisions. Merging your finances before there is a legal union binding you together can be magnitudes worse than even the most horrendous financial decisions.” 
... ancient scriptures elevate only the status of marriage for creating and nurturing children and families.
Of all possible living arrangements, ancient scriptures elevate only the status of marriage for creating and nurturing children and families. Paul said in Hebrews 13:4, “Marriage is honourable.” Over time, I have come to believe that doing the honorable thing has empowered me. Within marriage, I feel empowered when I act honorably for the benefit of our marriage.
For those who are feeling the need to divorce, I am sure you are experiencing significant pain, frustration and perhaps worse. Still, in most situations, it would be better financially, to work on improving yourself as a marriage partner, than it would be to divorce.
It may require a miracle, but I am certain “prayer can bring miracles to our marriages”.  However, if you are praying for God to change your partner, then I have little hope. God honors our agency and so He does not generally change others against their will. However, He can and will change you if you let Him and frequently, when one person changes, the relationship changes.
For example, in our marriage I've noticed that when I improve my behavior, our relationship improves. There are some caveats to this that involve trust issues. It takes time to build trust, but a good marriage covenant will help give you more time to learn and grow in the marriage.
For those who are cohabiting because you are afraid of divorce. I know there is pain in marriage and in divorce. But isn’t there also pain in cohabiting? And isn’t there pain and loneliness in living singly? Aren’t we always going to experience pain in our lives? So why not learn how to handle and manage the pain in marriage? Why not learn how to make little improvements in our marriage over time?
God can help us do this, if we’re humble and willing to learn from Him. With His help, there are skills we can learn and master. There are virtues we can acquire and develop that can make marriage become “more an exultant ecstasy than the human mind can conceive.”  Our Heavenly Father would love to help us acquire these skills. He would love to heal us if we would let Him.
This “exultant ecstasy” is real and if with God's help I can learn how to achieve it, then others can as well. (Perhaps the mentally ill or the mentally disabled will be not able to achieve this, but I know of one such couple that has.) If the journey of a thousand miles begins with a single step, then the first step may simply be reconsidering our attitudes and our next step.
 Warren Bennis and Burt Nanus, Leaders: The Strategies For Taking Charge (New York: Perennial Library, 1985) 20.
 Ibid., 24-25.
 Thomas J. Stanley, Ph.D., The Millionaire Mind (Kansas City: Andrews McMeel Publishing, 2000) 235.
 Ibid., 234.
 David B. Guralnik, ed. Webster’s New World Dictionary of the American Language, 2nd college ed. (Cleveland: William Collins & World Publishing Co., Inc., 1974), 1444.
 Stephen R. Covey, The Seven Habits of Highly Effective People (New York: A Fireside Book, 1990), 263.
 Jeff D. Opdyke, Financially Ever After: The Couples’ Guide to Managing Money (New York: Collins Business, 2009) 11.
 Stephen M. Bird, “Prayers Can Bring Miracles to Our Marriages,” stephenmbird.com, accessed November 25, 2012, http://stephenmbird.com/library/marriage-family/prayer-can-bring-miracles-to-our-marriages.php.