Why is the First Sacrifice Rejected?

Cain offers the first sacrifice in the history of humanity, according to the Bible (see Genesis 4)—and it’s rejected. Why?

Moshe Halbertal says it’s to teach that sacrifice doesn’t always work, it’s not a form of technology or a sure-fire tactic for spiritual manipulation.

What’s your theory?

I agree with Halbertal, but would add, it’s not just the first sacrifice, it’s the first religious ritual in the history of humanity.

Could the Bible be hinting in a radical or unconscious way that God is not the biggest fan of religion?