And in the process of time it came to pass that Cain brought an offering of the fruit of the ground to the Lord. Abel also brought of the firstborn of his flock and of their fat. And the Lord respected Abel and his offering, but He did not respect Cain and his offering. And Cain was very angry, and his countenance fell. (Genesis 4:3-5)
This is the first time an “offering” is mentioned in Scripture and the Hebrew word used is מנחה minchah. Typically this offering is considered to be a “fruit of the ground” offering — i.e. a grain offering of some type. Because Cain was a tiller of the ground, it is presumed that this is what was presented by Cain. However, this type of offering may have been presented by Abel, as well.
The passage says that Abel “ALSO brought,” not “INSTEAD brought” of the firstborn of his flock. In other words, it seems that Abel brought of a lamb from his flock in addition to a minchah offering. In fact, Hebrews 11 says that Abel brought “gifts” not “gift.” But here is the point: because he brought a lamb to be slaughtered upon the altar, God respected his minchah (grain offering).
I’ll put it this way: God respected the gift that came from the cursed ground — that which represents our works — because Abel acknowledged the blood of the lamb. The Bible tells us that, without the shedding of blood there is no remission for sin; apparently Abel understood this. And because Abel acknowledged this, God respected something that otherwise would have been considered as cursed.
You and I can’t do enough to save ourselves; right standing with God is accomplished only by belief in the blood of the Lamb of God. However, once we have been born again, we are supposed to walk in obedience to God’s Word, i.e. our works — our minchah. The Creator receives our works as acceptable when we have been reconciled to Him through the Messiah. This eternal truth was first introduced to us in the very beginning.
Blessings and Shalom,