Does God go against His very Own nature?

I am not so sharp on Theology, but I want to present to you something that I have been thinking about. God clearly says when something is bad and we shouldn’t do it. But God also said He hates divorce, meaning its some kind of evil, because God hates evil. Now, if God hates evil, why would He approve of doing it? Not just “allow” it in the sense that He gave us free will, because in that, it makes sense. In that point, God doesn’t allow x but because of free will, He lets it happen. But in the case of divorce or polygamy, God hated these because they are evil in His sight. The thing is, He didn’t say “its wrong and you shouldn’t do it, but since you have a free will, you can choose to or not to do it. But regardless, its still wrong” He didn't say that in polygamy or divorce. He allowed a form of it (regulated) even if He hates it and sees it as evil. So when we do it, its like “it's okay, as long as you are following the regulations”. So that goes against Him that He can’t view evil, yet He allows it (meaning He doesn’t count it as a sin). However, I’ve seen some answers like: “God doesn’t approve of divorce nor of polygamy, but because it still persists, its better to regulate it to minimize harm” By that logic, why can’t we just allow sins altogether because we continually sin, yet God bans it outright? And if God doesn’t approve of it morally, yet continues to do it anyway (by actually stating that we can do it and there is no sin in us if we do), then is He immoral because He goes against what He deems evil?