Prenuptial Agreements - Allowed?

Soon, if ever I get married instead of staying single I would like to have an absolute separation of assets/property. I understand that we make vows to our spouse and to God, but it is not a sin right?
Because, I would like to protect myself if ever somehow despite everything I can do to choose a good spouse - they become crazy and find some way to divorce *and* take my things.

I never thought about prenups before but reading about how in America when divorce happens and many men lose their belongings to their spouses - who sometimes are even adulterous, this makes me very concerned.

Edit: thank you for your answers. I think I'm coming around to understanding, I just feel like what is asked of us is very ideal - and maybe marriage might not be for me. at least not for now.