And then there's the other side of the coin, conservative Christians denying that people who say they are saved by faith really are saved by faith.

It goes something like this: Once the holy Spirit inhabits a person after they become saved, he changes them. Sinful lifestyle no longer appeals to them. So, those people over there who ignore what I know the Bible means about sin cannot possibly be saved. They need to get right, because they're bound for hell.

That argument is quite the slippery slide into salvation by works, but it's very common in the Evangelical world, despite that definitions of "Biblical" sin vary by denomination and even congregation, and of course by time period. (e.g. the churches I was raised in considered love of rock music and Hollywood movies to be evidence of an unsaved soul. Those "sins" are not emphasized nearly so much today, when even many conservative Christian musicians sing or play in traditional rock and roll style.)