The Cornerstone of the Family Structure
"Sometimes my addiction makes me think, what's the evil in adultery? So many goyim do it today. Is there something intrinsically wrong with it, besides for the Torah forbidding it?"
Even without the Torah, adultery completely destroys the fabric of the family structure. If the one thing that makes a husband and wife unique to each other is no longer in place, then why should anyone stay with his wife when she gets a little older or a bit overweight? Or if she angers him a little? He'll just say to her, "go to the other men you are with - let THEM deal with you!"... And she'll tell him to go to the other women he's with.. If there's nothing unique to keep the couple together, then there's no commitment. This means that the kids don't have a father who is committed to the family. And not only that, the kids don't even know if this man IS their father! If they're both doing it with others, then the kids may be from others too! And then what kind of commitment does the father feel to raising his children and providing for them, if they aren't even for sure his own? In short, there can be no family structure, no commitment and no responsibility to provide - if adultery is an accepted way of life. Even for those who believe in Evolution and the survival of the fittest (chas veshalom), they would find that in communities where adultery is accepted, the kids would grow up unbalanced, traumatized and abusive - and they wouldn't survive long. It is common sense. And that is why our Creator, who knows exactly how He created us and what we need for a healthy family structure of responsibility, commitment and for the father providing for his family, He commanded us to stay far away from such behaviors. And we get tremendous s'char when we listen to Him, even though it's really all for our own benefit all the way!