The biggest difference I have seen is that a lot of non Christians I know will stay with a bad fit rather than be alone. I have known quite a few people that will stay in a relationship for years with someone that they have no intention of marrying but will move in together and all that. Sometimes they trade up when someone better comes along.
One of the ladies I work with has been with the same guy for here years. I quit listening to her tell me about him 6 or so months back. Every time, it was about what a loser he is or how bad a fit they are. But he moved in with her last year. They are in this state of perpetually calling it quits and getting back together.
It seems most Christians I know would rather be single than on that state.
Something Cinder kind of reminded me of, and something brought up in another thread, was the idea that somehow needing or wanting companionship is some sort of weakness. But I was reminded again today that we are social creatures and need others for support and companionship. Not necessarily romantically. I think in my case, I felt like I should go it alone, or only depend on God. There is some other baggage to sort out, but I think most of my isolation has been due to feeling like I shouldn’t need anyone.