DID YOU KNOW?
The answer
None. Genesis 4:3-5 says Cain brought "an offering of the fruit of the ground" and Abel brought "the firstlings of his flock, their fat portions." Then: "the Lord had regard for Abel and his offering, but for Cain and his offering he had no regard" (Genesis 4:4-5). The chapter does not say why. It turns at once to Cain's anger (Genesis 4:5-6).
Why it’s interesting
The New Oxford Annotated Bible, a study Bible, says the story never spells out a reason, and does not support the many old and new attempts to blame Cain. The story may just assume God would prefer a fatty animal sacrifice. Michael Coogan and Cynthia Chapman, two Bible scholars, add that later tradition filled the blank with a story that Abel gave his best and Cain gave less.
Scholarly consensus
Learn the Bible.
Not just the stories, but the history, authorship, and scholarship behind it.