I have a rather negative image of Christendom, actually. Normally, I assume the person is either sheltered or hateful, and often hypocritical. I'm sure that is unfair. It's certainly not true of my handful of Christian friends, but in my experience, that sums up many Christians I've met.
Often, I don't think so. I've often been surprised, when I'm at a gay club where my best friend works doing female impersonation, and I'm introduced to people who are dancing, drinking, flirting -- and then I learn they are Christians, or they will say they have to go to bed before long because of church in the morning. Sometimes, I feel like correcting them, and I often feel I know a lot more about their religion's standards than they apparently do. It cements the opinion that some Christians are hypocrits, and encourages doubt because, if they believe and don't care to act pn them, why would I care what they have to say about their beliefs?
Now, sometimes people will take me by surprise. I have a great friend who is a Christian and a seminary student, who will be in what you might refer to as worldly situations, and yet he isn't "of" them, as the Christian term goes. But many Christians I've known seem to give in to 'the world' quite easily. One friend of mine was very involved with the punk scene a while, dressed like it, etc, but abstained from behaviours he felt would represent Christ poorly. However, he caved to peer pressure, started drinking addictively, started sleeping around randomly, etc. He was a Christian in name only, and indistinguishable from anyone else except that he claimed he was different.