Cain and Abel

So it came about in the course of time that Cain brought an offering to the LORD of the fruit of the ground. Abel, on his part also brought of the firstlings of his flock and of their fat portions. And the LORD had regard for Abel and for his offering. (Genesis 4:3-4)
Compared to disciples of Jesus Christ, Cain and Abel had little knowledge of God. As children of their parents, Adam and Eve, they began to learn about God.  They knew of their parents past home in the Garden of Eden. They understood how and why their parents were evicted. Cain and Abel were also able to experience the general revelation of God, as people can continue to do today (Romans 1:19-21). They could marvel at the creation, the awesome landscapes, fruitful vegetation and  many animals. Cain and Abel could also consider the fruitfulness of their labour. In short, they were not living in a culture of entitlement, as so many of us do today.
Cain and Abel brought offerings to the LORD. What prompted them to do this? What were the offerings for? Did the LORD require such offerings? God is sovereign, he does not need or demand from man. Yet, Cain and Abel, without any command or prompting brought offerings. The offerings were not likely for the atonement of sin. 
The term ‘sin’ is not used until after the offerings were made. Cain became angry seeing how Abel’s offering was regarded and his was not.  We now know more fully through Christ that Adam and Eve sinned in the Garden of Eden. However, at that time the LORD simply stated that they were disobedient. 
The LORD said to Cain: “If you do well, will not your countenance be lifted up? And if you do not do well, sin is crouching at the door; and its desire is for you, but you must master it.” In other words, while God is sovereign, he is not mocked, what a man sows he reaps (Galatians 6:7).
So if Cain and Abel were not making an offering for the atonement for sin, why did they both make offerings? Why was one offering regarded and the other was not? The scriptures do not give us much detail to answer these questions. Scriptures often say much in few words. God’s Word is often times, as is life itself, very profound and it leaves us in a state of awesome wonder as we ponder, trying to collect our thoughts. What follows is one potential reason for why the brothers made offerings.
The offering by Abel was given first to acknowledge the presence of the author of all creation, to honour him and then to express his thankfulness. Think of it as when one receives an invitation to a dinner reception. Often the guest brings a small gift - flowers, for example. Does the host need flowers? No, but the offering is  an expression to honour the host and then thank. It is a token of appreciation. This was the first of many things offered to the LORD God before Christ.
Why did the LORD God have regard for Abel’s offering and not for Cain’s? Cain did not hear from God why. Perhaps God could have taught him that lesson later? For that moment, Cain knew that Abel’s offering received God’s recognition or approval. Cain got so angry that he killed Abel.
Some have speculated that because Abel’s offering included the shedding of blood and Cain’s did not, the LORD God could not regard his offering. This is not likely the case, as grain offerings did not stop in Israel. Others have speculated that Cain was trying to give back to, or appease, God for what his parents had stolen in the Garden of Eden - a type of settling accounts. There was likely something else that led God to regard Abel’s offering.
Abel gave his offering with heart-felt appreciation and thanks. Whereas Cain gave his offering with a sense of duty or obligation. Abel’s offering was made because he wanted to do it. Cain’s offering was made because he thought he had to do it. It would be as if a guest gives flowers to a host with a motive to win favour and respect. Abel was not seeking anything in return, rather his motive was simply to acknowledge his creator, honour him and express his thankfulness without any thing in return. Abel wanted to offer, Cain considered he had to offer.
Cain was also likely scheming to find away to receive God’s blessing. If offerings is what will ‘do the trick,’ then offerings is a small price to pay. Offerings were more like a “lucky charm” for Cain. Abel, on the other hand, made his offering as something given that is appropriate and reasonable - a gift made without any expectation of a return.
The apostle Paul writes in Romans 12:1-2 that we are to present our bodies as a living sacrifice to God, as it is our reasonable service. While Cain and Abel did not have the instruction from scriptures, as we do today, Abel made his offering because he considered it a reasonable service - as it acknowledges, honours and thanks our creator - the LORD God.
Men judge the outward appearance, the LORD looks at the heart (1 Samuel 16:7). We can all look very similar in the outward but only God knows the motives. That is why Jesus said that there will be some that can even prophesy, heal the sick and cast out demons, all in his name and Jesus eventually responds “I never knew you, depart from me you workers of iniquity” (Matthew 7:21-23).
We have died and our life is hidden in Christ (Colossians 3:3). Those who call out praying to God, through Christ, in their closet (Matthew 6:6), can be rest assured that their relationship with Jesus is regarded (as God had regard for Abel’s offering). Jesus said that those who come to me I will in no wise cast out (John 6:37). An open and sincere heart for Christ, that no man can see, is what is regarded by our LORD God.
May we offer to God as Abel did and not Cain.