Things aren’t so cut and dry:

“Rhoades and Stanley used a representative sample of approximately 1,600 Americans who were married for the first time between 2010 and 2019. The study found that 34% of marriages ended among those who lived together before being engaged, while just 23% of marriages ended among couples who waited until after engagement or marriage to move in together.” - https://www.du.edu/news/new-du-study-highlights-risks-living-together-engagement

This was also an interesting read: Are Couples That Live Together Before Marriage More Likely to Divorce?

And that’s from Psychology Today, which is irreligious.