Sadly, yes. In an article by Naomi Schaefer Riley, in the Sunday, June 6, 2010, edition of the Washington Post, she notes that the American Religious Identification Survey of 2001 indicates that couples in religiously mixed marriages are three times more likely to get divorced than couples who share the same religious faith. There are also variations, usually more tragic, for those of differing degrees of religious belief.
The basic reason cited by Schaefer Riley is that most people don’t realize what a profound impact their religious heritage has on their approach and expectations of all relationships, including marriage. Often the degree to which they are influenced by their faith, even if they do not actively practice it, does not manifest itself until much later in the marriage. Most typically, this occurs after the birth of their first child when questions about the religious upbringing of the children come to the fore.
It turns out that the old adage, “The family that prays together stays together,” has much more sociological credence than folks were willing to admit.
Because of the tremendous challenges inherent in religiously mixed marriages, as well as the very real danger to the faith of the Catholic party, the Church prohibits them. A dispensation from this prohibition may be obtained from the competent diocesan authority, but there are no guarantees. Couples who are considering an interchurch or interreligious marriage need to be painfully honest with themselves about their prospects for success.