It's funny really, the way the main critera for "devoutly religious" seems to be bludgeoning people with your ideas.
That approach never really appealed to me, especially in this situation since it seems they were talking about all the stuff you are supposed to do to be a good person. Christianity (an assumption here, you never did say exactly what faith these girls are from...) does not, in any way shape or form have a monopoly on teaching or the concept of being a "good person" most, if not all belief systems have very similar ideas about what is right or wrong. What Christianity has a monopoly on is the person of Jesus Christ. Take him away and we have nothing.
It's pointless taking the "You bad person, you should be doing this and this... etc. etc." angle with people, it achieves nothing, save making them defensive, uncomfortable and angry. And aside from that, you just can't treat people that way! Jesus didn't and we shouldn't either.
Anyways, that's my rant for the evening 🙂
All I can say is that I hope you have some more positive experience with Christians in the future.