http://www.usatoday.com/news/health/2008-07-28-cohabitation-research_N.htm
This article says rates are higher for people who cohabitate before but don’t blame it on living together..
You need to read that USA Today study, it clearly says the study is not reflective and the numbers are skewed because the rates of cohabitation are much, much higher today that from earlier years, so the rates of divorce from any marriages would be higher.
Its not a scientific study its simply a cautionary tale.
So far you’ve not posted anything from religious spew, something from a “love” website and this, which cautions its readers to not take it for any statistical nor scientific value.