I saw a comment on a blog recently about credible Christians leading by example -- if someone says that hating people is wrong, then we would see the Christians consistently try to not hate. The whole idea of "walk the walk, not just talk the talk."
A comment in response to that essentially said that Christians cannot that credible, because they're as sinful as everyone else. The real focus should be on announcing Jesus and what Jesus has done for everyone -- that would be much more valuable than trying to be credible.
I didn't post a response on that blog, as my response would've been a tangent. Yet this idea I see - Christians as sinful as everyone else - is the same problem I had with Tim Keller's book. Mr. Keller was going with the idea that you should actually expect non-Christians to behave in a better fashion that Christians. The idea in this comment is that Christians will behave no better and no worse than non-Christians. An idea we all certainly see in everyone we encounter ... yet then where's the validity behind the conversion experience? Not only that, what's the value in the salvation? There's no evidence at all of this "healing" in this life? Then what confidence does one have for something in the next life?
If someone says that Jesus saved them, gave them a new life, a new mind or a new heart ... shouldn't we see evidence of any of this? Otherwise, how can you back up your claim? It would be like an overweight person claiming that drinking Slim-fast would help you lose weight, just like it helped him. However, a year of Slim-fasts later, the overweight person still weights 300 lbs. You'd have no "faith" in Slim-fasts ability to do what was claimed.
Plus, isn't the whole idea of what Jesus did tied to making the believer the "new man?" That we would know his disciples based on their love for people, that there the fruits of the Spirit that should be evident in believers. I mean, if one is going to proclaim that Jesus has done this great thing, that claim has to be backed up with credible support.
But if becoming a Christian means that they won't be credible in their message, that the message in fact doesn't deliver upon what it says ... why would anyone become a Christian? It becomes empty rhetoric.