This might not help some struggling couples but no, Christian couples do not divorce at the same rate as those who are not Christians. Several different sociologists have found that actively religious couples have a lower divorce rate. HT: Tim Challies
The factor making the most difference is religious commitment and practice. Couples who regularly practice any combination of serious religious behaviors and attitudes — attend church nearly every week, read their Bibles and spiritual materials regularly; pray privately and together; generally take their faith seriously, living not as perfect disciples, but serious disciples — enjoy significantly lower divorce rates than mere church members, the general public and unbelievers.
That may not help those Christian couples who are struggling. But it should encourage us to live differently than the world. It should also give our children another apologetic that faith and family go well together.