Ironic. My wife and I did exactly this, not to mention she was a divorce, and I'd had previous partners and yet... I never cheated on her... not once.

Why do we care what he thinks?

Typical bullshit

I have a feeling he's speaking from his own experience.

More pure christian BS (this preacher has probably cheated himself). I had sex before marriage but ended up marrying the woman (big mistake).

The percentage of cheaters among clergy seem higher than among others. My wife and I had sex before marriage and neither of us ever cheated.

There he goes again, talking out his ass.

Where is a Hatfield when you REALLY need one?
With him being a Preacher I'd lay Odds on Bets that he'd be an Expert at Cheating on EVERYTHING, including in marriage.

He was probably dropped on his head when he fell out of his mamas hole.

Where is his study? In reality, the studies that I have seen show that living together forms a more likely and stable relationship. Again, there are no guarantees.
Of course some studies show arranged marriages last longer - that is a poor analogy because often in those marriages the women are coming from harsher, controlling environments.
I read an article written by an Indian fellow who came out gay to his parents. They, being "liberal" minded said they accepted his choice, and then began looking for a suitable young man for him from a proper family.