There is no "right way" sex should be viewed; it's different for every person. My opinion on it...um, well, it's kind of in the middle? I don't see casual sex, ie, just fucking the first person you see without any thought at all, is a good idea. I don't think you should associate THAT kind of detachment with something that is, after all, inherently intimate. But it isn't sacred. Sorry. You're needlessly glorifying it and are setting yourself up for a lot of frustration and heartbreak if you think sex is something reserved for marriage. (An institution that was once important, but has since become watered down into the realm of "Casual" thanks to high divorce rates. I don't like it. I still take it very seriously, but this is how the world is now.)
I'm going to be frank here. Men and Women are both programmed to enjoy and seek out having sex. Sure maybe for guys it's more direct, and for girls it's more emotional, but it ultimately leads to the same place. If you're in a relationship, sex is an important part of connecting and solidifying that relationship. People change after they have sex. The relationship changes. And sometimes, not for the better. If you wait until you're married, you're putting yourself at risk of causing the dynamic of your entire relationship change with no easy way out. Does that sound selfish? Maybe. But how bad would it be to discover you can't love a person fully because you're incompatible sexually after you're married? Sex is an important part of any relationship. And if it isn't working, it can only breed disappointment, anger, resent and eventually hate.
TL;DR: Sex is not sacred nor should it be abused/tossed away. If you like someone, do it. Literally. You will be happy you did, one way or the other.