In defense of marriage:

Mrs COMMON CENTS and I attended Mass in Western Pennsylvania last weekend as we were attending a fall festival. At the church we went to the priest gave a interesting and factual defense of the sacrament of marriage.

Nearly 60% of adults are married, 10.4% are separated or divorced, 6.6%
are widowed, 19% are never married and 5.7% are living with a partner.
Marital status varies greatly among race/ethnic groups: approximately 61
percent of white adults, 58 percent of Hispanic adults, and 38 percent of
black adults are married, according to the survey.

Married adults are less likely than other adults to be in fair or poor
health, and are less likely to suffer from health conditions such as
headaches and serious psychological distress.

Married adults are less likely be limited in various activities, including
work and other activities of daily living.

Married adults are less likely to smoke, drink heavily or be physically
inactive. However, married men are more likely to be overweight or obese
than other men.

Adults who live in cohabiting relationships are more likely to have health
problems than married adults and more closely resemble divorced and
separated adults.

The association between marital status and health is most striking in the
youngest age group although it persists throughout the age groups studied.

Read more about it here:

Even the New York Times recently chimed in with an interesting article:

Single people may simply not know what's good for them, a recent group of studies suggests. A body of demographic research presented at the conference of the Population Association of America here today indicates that marriage offers dramatic emotional, financial and even health benefits over the single life and cohabitation. "Cohabitation has some but not all of the benefits of marriage," said Linda Waite, the association's president, in an address to members in which she argued that the married enjoy better health, more money and more satisfying sex. An enhanced commitment that comes naturally with marriage, she said, increases all levels of the support that individuals bring to their relationship and lives. "Cohabitation does not generally imply a lifetime commitment to stay together," she said. "Cohabitants are more likely to assume that each partner is responsible for supporting him or herself." Dr. Waite, a professor of sociology at the University of Chicago whose research focuses on family structure, drew from various resources in her work, including the National Survey of Families and Households, a sampling of 13,000 adults, which was conducted in the late 1980's, with a followup in the early 1990's. In terms of money, her research found that married couples were generally more financially well off than couples who simply lived together, because they were much more likely to pool money and invest in the future than were couples who merely cohabitated. Increased material well being, she argued, trickles down into investments in better medical care, safer surroundings, better food and other things that raise the standard of living and reduce stress. Read about it here.