In fact, faithful Catholics have one of the lowest divorce rates in the country. From Divorce Statistics Collection:
In truth, the National Institute for Healthcare Research says weekly churchgoers throughout the U.S. are less apt to divorce than people who claim "no religion" and those who attend religious services less than once a week. Devout Catholics have especially low divorce rates - apparently because Catholic parishes often take the responsibility of marriage preparation and enrichment more seriously than Protestant churches do. Thus, one of the reasons for the relatively low divorce rates in the Northeast and Midwest is because these regions tend to have a higher concentration of Catholics than do other geographic areas.