The Bible has all the answers to this very issue one just needs to go find them and apply them. What I suspect is that sin is so seductive, it becomes a case of people justifying their participation on a variety of grounds.
Psalm 101:2-4 I will behave myself wisely in a perfect way. O when wilt thou come unto me? I will walk within my house with a perfect heart. I will set no wicked thing before mine eyes: I hate the work of them that turn aside; it shall not cleave to me.
Psalm 141:4 Incline not my heart to any evil thing, to practise wicked works with men that work iniquity: and let me not eat of their dainties.
Indeed.
Excellent scripture finds.