Christians are often teased and looked down upon as inferior, uptight, closed minded, intolerant, immature, childish, arrogant goodie goodies.
People will tease if someone is a "goody-goody" and what they mean by it not that it's bad to do good but that you act as thought you can't relate with them. I believe there are many people who don't even give a chance, they look down on people who don't do bad things because they've been consumed in doing these things, in this case it's their fault and the innocent doesn't carry the burden of blame.
There is another and much more common situation, though. I've found that the people who do "bad things" can be some of the most understanding and open minded people around. I have a good friend here at APU who likes to drink. He’s the only one here who doesn’t profess to be a “hardcore Christian” and yet , ironically, is the nicest guy I know.
The "innocent" are often guilty of closed mindedness. They flee from "sin" and make no effort to understand or befriend the "bad" people.
If you hang out with people who use profanity and gasp at it you are doing nothing to help the situation. Your friends will probably tease you. I would probably tease you. Is it really such a big deal? this, by the way, is only valid example if you have a problem with people using profanity. I have lots of friends who use bad language. They have never heard me use it and probably never will but they would never consider me closed minded about it. I have had several conversations about the whole language issue. I try to understand it's justification and they try to understand it's potential harmfulness. I have enthusiastically decided it's not that big of a deal. Why should I gasp at the F word without even flinching at world hunger. There are much bigger problems in the world.
Now if you honestly see how something is messing up someone’s life and respond in authentic concern for their well being it's noble. We are called to act in compassion. but what must be understood is that you are their friend and you totally understand. If you don't understand ask them, converse, understand their justification and hopefully they will try to understand your concern as well. Going to them and saying "what you are doing is wrong and this is why..." gets you nowhere and they will never understand that life could be better for them.
Someone who is truly in touch with what's going on around them will have a sense of perspective.
saying "the F word" does not send you strait to Hell. Could it cause bigger problems? this post is not about that but maybe. Sleeping with someone before you are married is not the unforgivable sin but I will say it is highly destructive though, address this issue with utmost courtesy. A drink at a bar is not poison (though for some it's about the same).
Don't flee from sinful people because chances are you're fleeing from yourself.
It's ok, if you are a mature adult to hang out with people who don't share your moral standard. I find it much more important to love and be relational than to point out everyone's sin.
If people tease you for being uptight or closed minded or immature it may be true. Does it mean we should party and cuss and drink, of course not. God calls us to the best possible way to live. If you think drinking and cussing are essential to that way of life your deceived but if you think those things automatically keep you from it you might also be deceived. Someone who professes Christ may be pretty on the outside, they don’t do anything wrong, but may be “whitewashed tombs” filled with death. You must discern if something has become destructive in someone’s life and don't condemn until you know (even then don‘t condemn… but you know what I mean). Talk to people and learn why they do what they do. Learn perspective.
I'll leave you with a story I heard from a friend.
Tony Campolo was speaking at a pastors seminar. He was telling a story of a prostitute who'd felt rejected by the Church. her response to a man who'd invited her to church was "why should I go there? I already feel bad enough about myself." Tony went on a rant he said "how despicable is it that the church made her feel that way..." He went on "you know what? that's sh*t!" A pause and silence went through the crowd of pastors.. Tony waited... then he said "now I bet you are more appalled that I said the 's' word than you are at the way the Church made this woman feel."