Also . . . there is the story (admittedly fictitious -- don't you agree?) about Jepththah and the daughter he sacrificed. Here is Wikipedia's take on things:
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Another instance of human sacrifice mentioned in the Bible is the sacrifice of
Jephthah's daughter in
Judges 11. Jephthah is victorious in battle against the children of Ammon and vows to sacrifice to God whatsoever comes to greet him at the door when he returns home. The vow is stated in
Judges 11:31 as
"
Then it shall be, that whatsoever cometh forth of the doors of my house to meet me, when I return in peace from the children of Ammon, shall surely be the LORD's, and I will offer it up for a burnt offering." When he returns from battle, his virgin daughter runs out to greet him. That he actually does sacrifice her is shown in verse 11:39 "
And it came to pass at the end of two months, that she returned unto her father, who did with her according to his vow which he had vowed". This example seems to be the exception rather than the rule, however, as the verse continues "
And she was a virgin. From this comes the Israelite custom that each year the young women of Israel go out for four days to commemorate the daughter of Jephthah the Gileadite.".
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Well, as unfortunate as that tragedy was, Jehovah, who evidently was in regular communication with his favorite guy (Jepththa), didn't object to this bit of child sacrifice.
Let's assume a few things:
1) Jehovah is all-powerful, all-knowing
2) Jehovah knew that Jepthah was about to sacrifice his daughter
3) Jehovah could have intervened to save an innocent life, but chose not to.
So, we can safely conclude from that story that Jehovah doesn't object too strongly to child sacrifice, if at all. Contrary to the prohibitions against such things of Leviticus 20 (see above), Jepthah was not punished for what he did, even though he did what he did in full view of Jehovah. Thus, child sacrifice is not, as you allege, "at the top of God's list in things that are punishable by death."