There are those of us who are faithless and yet don't drink to excess, sleep around, or otherwise engage in debauchery. On the flip side, let's consider some of the basketball players I knew of at school/follow on twitter. Most are nominally Christian, many have Bible verses or affirmations of their faith in their 'about me' section there, and most do all of these things. I can still remember the first time my old manager friend told me about 'wifeys' vs the girls on the side that almost every player had and I was inwardly horrified. Of course, if all the girls knew about each other and were OK with the situation, that would be different, but somehow I doubt such a large proportion of the student body would be openly polyamorous like that... I am digressing from my point, though. 

The point being that once we start throwing labels into a situation, it becomes more complicated. And 'Christian' is a BIG, BROAD label. There are thousands of denominations, probably millions of different interpretations of what Being A Christian means. I would be willing to bet that if you asked a thousand Christians about what Being Christian entails, you would get a thousand different answers. So if you say a person will be hated for Being Christian... well, what exactly does that mean? It depends entirely on who is making that statement. Clearly the players I mentioned before have a different interpretation of what that means than you do, just as you have a different interpretation from my Mennonite neighbors. Now purists of the faith may say that Jesus said to do X, Y and Z and any deviation from these things is misinterpretation... but this is true of almost every denomination, is it not? They all think they're right, otherwise there wouldn't be so many! And the nature of literature is such that a case can be made for almost any viewpoint, even when they're diametrically opposed to one another. People can't agree on what Shakespeare meant, never mind Jesus!

So where am I going with this. Ok, let's look at your example. You propose that this Christian girl's sorority sisters dislike her because she's never done a Walk of Shame (obviously I'm paraphrasing, you know that I get what you mean). I don't think this has anything to do with her Christianity, unless she's very preachy and goody-two-shoes about waiting for marriage, but you've not said this about her, so I'll assume that isn't the case. There are a lot of elements at play here, most of them cultural. If the other girls feel judged for their promiscuity, it is something that they are putting upon themselves. Why is this? If they are otherwise mentally healthy, are not being coerced into sleeping with many partners, and are using appropriate protection, I would say that there is nothing wrong with their behavior. (Obviously if they're doing it for the wrong reasons something is awry, but this is psychological, not religious.) The unfortunate cultural trope is that men who sleep around are studs while women who do so are sluts, which is an antiquated notion at best. Girls can enjoy sex, too. Even casual sex! Why didn't you use the example of a Christian guy in a fraternity in this same situation? Probably it didn't occur to you, because men in this culture aren't expected to be pure snowflakes, and in that stereotypical situation it would probably be the virgin guy who would be put upon by the other frat members for being a loser/weirdo/etc. where in your situation you have elevated the virgin female (so really it is you who are being judgmental in this case, not them). This is again less to do with Christianity and more to do with our culture than anything. Also, since we're speaking in stereotypes, let's remember that girls in a confined space like a sorority house will probably find reasons to hate each other anyway, regardless of religious affiliation. 

And one last question- you needn't answer it, but something to think about- do you believe that if the girl in question was not religious, but simply wasn't a fan of heavy drinking or promiscuity, would the reaction of the other girls be the same? 

Now you know that I like and respect you, and you know that I understand where you're coming from. Your interpretation of your faith means that you must do x and you mustn't do y and so on and so forth. So I will put this as nicely as I can- yes, as a person of faith in a secular society, it is you who must do the compromising if you care to be friends with us, the Godless. Because to us, your rules are arbitrary, and asking us to follow them is just silly. Imagine if you were spending time with the Amish and they wanted you to stop using electricity, wear plain, homemade clothes and grow a chinstrap beard. Extreme, no? Ah, but their branch of Christianity tells them that is what is required of people! But you say wait, the tenets of their faith don't apply to me- well that is how we feel about religion, period!

If you abstain from some things, it won't cause you to be hated (so long as you are friends with reasonable people). Whether you abstain because your arbitrary rules say you must or because your tastes are simply different doesn't make a difference. But if you abstain from a thing and make a fuss about it because of your arbitrary rules and imply that others shouldn't be doing it either, even though they have no expectation of heaven or hell or all the rest of it, that is where dislike will come from. You absolutely have every right to believe what you like and you even have the right to proselytize, and the godless have just as much right to say hey, dude, that's annoying, cut it out- and to stop hanging out with you if you don't. You can also choose not to be friends with the Godless, if it bothers you that much.

Whew, that was a rant. If you made it through all this, I congratulate you on your patience. Apologies if I've missed the point entirely. (Also for the record I think you would look cool with a chinstrap beard.)