New believers should be encouraged to add 1 Cor 5:12 to their memory verse list to nip this stuff in the bud: What business is it of mine to judge those outside the church? Are you not to judge those inside?
And of course the judging within the church mentioned here involved a continuing sexual relationship between man and mother-in-law, not the height of a teenager’s hemline or the amount of thigh jiggle.
There’s a very strong biblical case — maybe a command — for Christians to be mindful and considerate of the struggles of fellow believers. This is inward looking though, not outward looking. I can choose to refrain from certain things if it supports the needs and struggles of my community, but I don’t see the case for how I can impose the same restrictions (aside from the don’t sleep with your mother-in-law thing) on another person. As was rightly pointed out, Jesus said to gouge your eye out, not berate the object of your lust.
I’d love to do away with the earnest Christian vocal affect. Speak with your adult voice, not that of some poor Marilyn Monroe impersonator. The moment you hear that breathy voice, guard your heart and wallet.