Maybe it's just me, but somewhere along the way, I think Christians got the idea that we're supposed to be changing people. We're supposed to convert those around us from sinners into saints. From lost to found. From messy to clean.
The promiscuous teen. The alcoholic co-worker. The cheating husband. The deceptive wife. Each, seemingly, is the perfect target for a Christian's help. For our answers. If we just talk to her or have lunch with him, we can "fix" the issue and (just maybe) bring up Jesus in the process.
Personally, I think we've gotten it backward. Over time so many Christians have been groomed to believe that it's our job to lead those around us to purity, sobriety, monogomy, honesty or whatever. We believe that it's our job to bring about change in someone's life. To, somehow, elicit an attitude or lifestyle change before Jesus ever changes their heart.
Expecting someone who doesn't know Christ to live like they do is absurd. It's putting the cart before the horse. Without any compelling reason to change, there's really no chance that they'll even try.
As best I can tell, the only place that Christians are called to lead people to...is to Christ himself. He takes care of the heart...and the lifestyle follows. Not the other way around. God specializes in sinners. He loves the lost. He majors in messy. You and I are simply asked to point people to Him as best we know how.
True change happens not when we present perfect people to Jesus, but when we present a perfect Jesus to people. That requires you working on you and me working on me...not us working on them.