How to argue against this claim

[Jenny A]

Hi All,

So Obviously the Bible and god ways are full of evil deeds, and EVIL agenda
Slaves, murders and much more

Some Religious person would say,
Yeah but think of a child that sees a doctor cutting a man legs to save his life.
So like us the child lack of understanding the big picture.

Please give smart way to explain this comparison

Thanks

AND after allowing the child to see him cutting the legs off a man to save his life, the doctor writes a children's book about it so future children can also be traumatized. Does he explain why he cut the legs off the man in the crappy book? He does not.

Fun---

But really, the original analogy is just special pleading. It is a rather graphic version of God works in mysterious ways. God is good, so if he does good stuff it shows he's good, and if he does bad stuff, then it's really just our misunderstanding.