We don't know the reason for Abel's sacrifice...
Yes we do. It says in Genesis 4 that both Cain and Abel brought מִנְחָה - that's a tribute paid to a king. Not for atonement.
But with regard to Israel: "For the life of the flesh is in the blood, and I have given it to you upon the altar to make atonement for your souls; for it is the blood that makes atonement for the soul." (Leviticus 17:11)
This is a given. Try to keep up... the question is, if God commanded sacrifices, why then does He say things like:
Hosea 6:6 I desired mercy, not sacrifice;
Isaiah 1:12 I delight not in the blood of bullocks, or of lambs, or of he goats. When ye come to appear before me, who hath required this at your hand, to tread my courts? Bring no more vain oblations; incense is an abomination unto me; the new moons and sabbaths, the calling of assemblies, I cannot away with; it is iniquity, even the solemn meeting. Your new moons and your appointed feasts my soul hateth: they are a trouble unto me; I am weary to bear them.
There is a troubling dichotomy in the Old Testament.
Half the books (Exodus, Leviticus, Numbers, Job, and all the books of OT history) are all about the priesthood and atonement and sacrifice, and nobody is justified without blood. The things written appear to be literal, and meant to be literally performed.
But in another group of books (Deuteronomy, Psalms, and all the books of prophecy), sacrifices are abhorred and not accepted and people are justified by believing. Often commands are (re?)interpreted in a way other than literally. Psalms 78, for instance, recaps all of the history of Israel, and calls it "parables."
1M1M has followed Barnabas' interpretation, holding that most of the commandments are not for literal observance, but rather meant to be interpreted.
How do
you resolve the apparent conflict?