So you didn’t read the Bible (nor the Koran), then; just admit it. Instead, you read the propaganda of others. Nothing mercurial about the God of the Old Testament whatsoever, who gave Israel and Judah multiple warnings and multiple chances to stop their idolatry and child sacrifices.
There is also another chief difference between the God of the Bible and Allah: the former specifically claims the title “Father” whereas the latter is adamant about not having any children.
Mercurial:
changeable; volatile; fickle; flighty; erratic:
“Old Testament God”: created man, decided they were too violent without telling mankind that being violent was a bad thing. Destroyed Man with flood. Saved Noah, who then got drunk and cursed an entire tribe of men because its found saw him naked.
God creates a wealth of food in Egypt for seven years, then causes a famine of equal time so Joseph can make bank on stored Egyptian goods.
To punish ALL Egyptians, and not just the ruling class, OT God kills all the Egyptian first-born and when he runs out of them, kills first-born cattle to boot.
Yep, that’s mercurial.
You are quite wrong; I had a Koran in the 1990s because I wrote a diatribe about Islam in grad school. Of course, my liberal professors disagreed with me about what a misogynistic, aggressive religion it was. But they kept denying it even on Sept 12, 2001, so...
I am familiar with them both, and it is definitely the Old Testament God, Mr. I-am-a-jealous-god, go-kill-the-Canaanites, no mention of rape being morally wrong, dire threats and warnings and on and on... yes, that's the God the Muslims built on. Oh, they added their own take, just as you have, but it's clear that the Bronze Age, patriarchal God of the Middle East moves seamlessly from Israel to Lebanon and Syria.
And I seem to remember your God wanting a child sacrifice. Isaac, wasn't it? He was spared, of course, but God was pleased that Abraham was willing to do it. Yes, that's a god the muslims recognize quite readily.