Other writers, whether accepting or rejecting the Documentary Hypothesis, point out that there is no disagreement here since Abel could have performed animal sacrifices, though he himself ate no flesh. Very often it's been held that one of the main points of this account is that God requires blood for expiation of sins. However, there is no reference in the account of Cain and Abel that the purpose of the offerings was to expiate sin. More importantly, there's no reference to Abel offering blood; just a seeming reference to "fat". If a major point in this account is the importance of blood for the forgiveness of sins, wouldn't it make more sense that the blood would be mentioned instead of the fat?