When asked the main lesson of Cain and Abel in Genesis, specifically why God accepted Abel’s offering yet rejected Cain’s, most will tell you it’s because Abel’s heart was in the right place. Unlike Cain’s.
God even told Cain why his offering was rejected: “Surely if you do right [t]here is uplift. But if you do not do right, sin crouches at the door; its urge is toward you. Yet you can be its master.” (Genesis 4:7 TNK)
I mentioned this in a comment section of an article called “What the Bible Really Says About Tithing.” Someone then responded that Cain’s offering was rejected because it was a “fruit of the soil” offering, and not an animal. This person reasoned that blood sacrifices are found all throughout scripture as a way to eventually point to Jesus, the Messiah, as the ultimate and final blood sacrifice for our sins.
I don’t disagree about the importance of blood sacrifice for the forgiveness of sins, and how they do indeed point to Jesus. I do disagree, however, that Cain’s offering was rejected due to it not being an animal.
The passage itself states why in Genesis 4:2a-4a: “… Abel became a keeper of sheep, and Cain became a tiller of the soil. In the course of time, Cain brought an offering to the Lord from the fruit of the soil, and Abel, for his part, brought the choicest of the firstlings of his flock.”
Notice the difference in how the offerings were described. Cain merely brought a portion whereas Abel gave the choicest of his firstlings.
Many other scriptural passages describe plant/grain offerings including Deuteronomy 18:4: “You shall also give him the first fruits of your new grain and wine and oil, and the first sheering of your sheep.”
Deuteronomy 26:2: “you shall take some of every first fruit of the soil, which you harvest from the land that the Lord your God is giving you…”
Deuteronomy 26:10: “Wherefore I now bring the first fruits of the soil which You, O Lord, have given me.”
Leviticus also included grain sacrifices as long as they were “first fruits” such as in Leviticus 2:14.
Not all offerings or sacrifices must be of the animal variety. That would be patently unfair (in my opinion), because not everyone did (or could) raise animals.
Back to Cain. The fact he didn’t offer his first fruits was the first indication his heart was bent toward sin. He either didn’t love or fear God enough, or didn’t think God would notice (or both). Either way, his offering showed selfishness and contempt. No wonder God rejected it.
Cain killing Abel later was merely the end result of what had already poisoned his heart.
Still regardless of how one reads the passage, the overall lesson is still clear: before we give either to God or to others, our heart must be in the right place. To give gladly and not begrudgingly, otherwise what we give is both useless and meaningless.