Lukewarm

Hey guys! I feel like this is a question I should have an answer to, but I could use a straight-forward answer. So, I have friends who are lukewarm Christians, and they kinda criticize it...I don't know how to describe it, but basically they hate lectures, retreats, singing, discussing their feelings, and I guess just getting out of their comfort zone. (Maybe you know people like that?) For example, I had a great time at our school's retreat (thanks Haley!), but they complained for, like, 15 minutes straight about how stupid it was. Anyway, I don't really know what to say to that. If I tell them I liked it, they say they agree with me, but then go on to criticize it. I don't know what to say! Does anyone have any suggestions? Thanks! -Erin