One of the most critical values my husband and I try to teach our three teenagers is the importance and joy of marriage.

After my desire for my children to be at peace and have a personal relationship with their Creator, my second greatest desire is that they would one day be happily married and raise children of their own.

Why? Because I know the joy of this great blessing, and because I've seen the pain and heartache of divorce, out-of-wedlock births and single parenting. Yet our modern culture refuses to spread the truth because it is politically incorrect.

But the truth is clear: God's design is for children to be born of and raised by two married parents. Sadly, we know that many people cannot help the fact that they're raising their children alone. But many others actually make the choice to raise children by themselves - and the children are the ones who suffer.

Many people fear being so blunt. But gutsy author and researcher Kay Hymowitz knows the importance of speaking the truth. She boldly detailed at a speech before a large audience at The Heritage Foundation how research proves that children and mothers who are part of families that include fathers and husbands are far better off than those moms who try to make it on their own.

But what about the "Murphy Browns" out there? Aren't there waves of high-powered career women happily having children out of wedlock, too?

You'll find some, all right. But not nearly as many as the sad, struggling single mothers and children living in poverty. In her new book, "Marriage and Caste in America: Separate and Unequal Families in a Post-Marital Age," Hymowitz explains:

Starting in 1980, Americans began to experience a widening Marriage Gap that has reached dangerous proportions. As of 2000 only about 10 percent of mothers with 16 or more years of education - that is, with a college degree or higher - were living without husbands. Compare that with 36 percent of mothers who have between nine and 14 years of education. All the statistics about marriage so often rehashed in magazine and newspaper articles hide a startling truth. Yes, 33 percent are born to single mothers … but the vast majority of those children are going home from the maternity wards to low-rent apartments.

How many single-mother families will you find living below the poverty line? According to Hymowitz, 36 percent - more than one out of every three. How many married couples? Only 6 percent, or about one out of every 20. That's a huge difference - one that Americans need to hear about. But good luck finding any class-warfaring politician who will admit this crucial factor. It's just too explosive. It's not nice.

Why do we find such a gap? Conventional wisdom blames the lack of decent "marriage material" out there: Too many potential husbands for low-income women are flipping burgers, unemployed or in jail, the story goes. But, Hymowitz notes, three facts cast doubts on this theory. First, middle-class men with decent jobs are avoiding marriage, too. Second, cohabitation among low-income couples has been increasing; why aren't the men who are good enough to cohabit with good enough to marry? Third, marriage makes even low-income women and children better off financially.

Perhaps we should ask why well-educated women opt for marriage in such overwhelming numbers. After all, they're better able to shoulder the financial burden of raising a child on their own - and yet they don't. Because, Hymowitz says:

Educated women know they'd better marry if they want their children to succeed academically, which increasingly is critical to succeeding in the labor market. The New Economy may have made single motherhood a workable arrangement for high-earning mothers in purely economic terms, but it made a husband a must-have in terms of child rearing. No one understands better than an Amherst or Stanford B.A. that her children will have to go to college one day … if they are to keep their middle-class status.

What do husbands offer? Added income, to be sure, and a helping hand with the kids. But it's more than that; after all, a cohabiting partner could do as much. "As society's bulwark institution, traditional marriage - that is, childbearing within marriage - orders social life in ways that we only dimly understand," Hymowitz writes.

Our Founding Fathers had a good grasp of it, though. "To the institution of marriage the true origin of society must be traced," James Wilson, a member of the Continental Congress, wrote in 1790. Growing up with married parents reinforces the values that underlie Western civilization: virtue, self-sufficiency, industriousness. In short, self-government begins at home.

That's why marriage matters. Its decline among the poor perpetuates something our country was founded in part to abolish: a permanent underclass. A growing body of social-science research shows that children in unmarried households are far more inclined to suffer from a wide variety of problems, from increased drug and alcohol abuse, to crime and school failure. They're also far more likely to not graduate from college and to have their own out-of-wedlock children - and the cycle continues.

That's not to say the cycle is unbreakable. But we can't hope to do so until we begin talking about the problem openly. So take your pick: Speak up and hurt some feelings. Or stay silent and hurt millions of children. What's your choice?

Rebecca Hagelin is a vice president of The Heritage Foundation and the author of Home Invasion: Protecting Your Family in a Culture that's Gone Stark Raving Mad.