My views on this are a lot different and maybe controversial but take from it what you may.
I see guys get upset with other "supposedly Christian girls" going to the club. I say turn it on its head and use it to your advantage. Even as a Christian male, I think going to the clubs is single-handedly the best thing to help you master social dynamics (after lifting of course). Depending on where you live you have the opportunity to talk to at least 15 cute women, 5 really cute women, and maybe one bombshell on any given night. You can go out with these "supposedly Christian girls" and have fun and display the good qualities you should be building.
As a Christian, it should be even easier to talk to them because unlike the secular world your goal is not to have sex with them, but to master push-pull, become more physically dominant, projecting your voice (because if you do not the person you are talking to cannot hear you, etc.) It makes you more comfortable going for the number, setting up the date, etc. It also makes you get comfortable with rejection. You will also become motivated to lift if you look like a pencil.
Now I cannot say these girls will be "girlfriend material". I only have one reference point, the girl before my wife and that was a bad relationship all around (on both sides). I met her at a bar in June 2017. I tried to get her to come to Church with me (she grew up going but stopped when her dad died (two months prior)). We had been dating for two weeks and I asked her to come to church with me. At first, she was on board but then she basically ran because it was too much. I felt her slipping away the next week so I went to her apartment on Friday night with flowers and her roommate answered the door. I heard some moaning in the other room and we all know how that story goes.
So on that point, I do not know if it is worth trying to convert these girls at least in the way that I did. The only downside I see to this approach is it potentially could make you become a womanizer and putting being good with women as your mission instead of making disciples for God. I cannot say how to balance that since I am no longer single, but it is something to think about.