Christianity, or is it?

So this is my first post and I did not think that this is what it would be. See today I saw a devoted "Christian" girl making out with a boy, who I think, is also a devoted Christian. Said girl (referred to as G from now on) has told her friend way before about abstinence/abstaining from making out with anyone because, supposedly it's "impure." Well okay, that's their opinion. But if you went along bitching about it before, then why are you making out then? Isn't it considered impure? or are you like every other supposedly "devoted" Christian that sins the hell out 6 days of the week and begs Christ for forgiveness on Sunday, and BAM, theyre forgiven? I don't think these rules are the true ways for a "devoted Christian" to act because they always bitch to others about how to "turn to God" and stuff, but them themselves are turning away from it all. That doesnt bother me one bit, but doesnt it bother all of you other Christians out there? So there she was G and her little boyfriend (B) making out like there was no tomorrow. Seriously! They made out for like 5 minutes straight, rested a couple minutes, then went right back at it. And let me tell you, it was no pretty scene. Most people would say "Oh, theyre just young kids. Who are you to tell them whether they should kiss or not?" Well okay, thats true. But theyre BELIEFS say that they supposedly shouldn't kiss. Of course, i'm no Christian expert, i'm not even a believer, but I do know that G told her non believer friend that she shouldnt make out/have sex till married, and there she is, in wide view, making out.
So this leads me back to the "sin all you want then come Sunday, ask for forgiveness" thing. Why do that? Do you really think that God would honestly forgive you every single Sunday for the shit you did over the week? If so, then this God everyones falsely worshiping has no clue as to what hes doing. Sure you may ask for forgiveness once, maybe twice in your life, and expect it to be rewarded. But every SUNDAY? that's bullshit! if you sin that much, then you dont even deserve to be forgiven the first time you ask for forgiveness. Seriously! go reread your bibles and then tell me if you should be following this modernized way of Christianity. Because wearing a cross around your neck and going to church every sunday JUST to ask for forgiveness or kill sometime, does not make you a true believer. So either try to do better OR simply just become an Atheist =].