RE: Christains told me that killing babies is fine
No, you still don't get it. What you're writing is proof of madness. What Abraham did was proof of his obedience, trust, faith and humility. And he did it with a heavy heart. It was not: "Cool, God ask me to sacrifice my only son, let's do it. I was waiting for that". He understood the authority of God. And his promises. If you read more about his story you can see that his only son was given him by God's promise. And also he was promised to have great nation from his son. So he trusted God will do something great. When people are doing the same thing it's not always the same thing. Even this story shows great love of God because he spared Abraham's son (although he tested his obediance) and he gave His own Son Jesus to save us as a sacrifice for our sins. You need more wisdom brother, your thinking is too harsh. Word of God (Bible) is great source of true wisdom but you need to read it in humble position, not with prejudice.
Yes, it is a proof of madness. and by your own admission Abraham was a mad man, because he did exactly that. he trusted God so he was willing to murder his own child when God told him to. Is it proof of obedience? Don't give new this crap that he was "just" obedient. No he was not only obedient but also attempted to murder his own child with a knife. Don't you realize that you can be both obedient, faithful and pants on head insane? The point is, you have already condemned Abraham, you just didn't realize it.
Things we don't understand seems to us often like madness. It's quite natural and understandable. When understanding increase, these issues are resolved. For example when God commanded Israeli people to kill certain tribes, it didn't comply my idea of loving God. It took me about 20 years until I get proper understanding about this and why it happened. But if I was prejudiced I would never understood this because I would stayed in ignorance of "my own knowledge and opinion". Fortunately I just said, I don't understand and hopefull God will give me understanding later. God's knowledge is ultimate and his ways are perfect. But our understanding is not.
And you are the one who is prejudiced. When I see a man that needs to be stopped , because he is about to slit his little boy's throat, it's not prejudice to assume that there is something horribly wrong with him. You are prejudiced becasue you ASSUME that it was all cool so you INVENT scenarios that would fit your narrative. I repeat: Make a statement that if you were Abraham, you would also make an attempt to murder your own child. If you don't do it, than you admit that what God asked Abraham to do and what he agreed to was hideous and immoral.
You'd do good if you try to stop any man to protect his child because it's according to your best conscience about what is good in such a situation. No one would blame you. Yes, Abraham's case was special and extreme. If someone tries to do it, it will be in 99,99% wrong thing and horrible deed. It's always difficult to judge without knowing a complete pictutre. You can be right in 99,99% cases but it doesn't mean that you're always right.