Abel's offering was accepted but Cain's was not, but he was told if he did well be would be accepted. No doubt they had been told, arising from the lesson of their parents' sin being covered by a slain animal, that "without the shedding of blood there is no remission". Hebrews 9:22.Hebrews 9:22XWaiting for response Abel's offering, motivated by belief, witnessed he was righteous. Hebrews 11:4.Hebrews 11:4XWaiting for response The lesson is that we be counted righteous but we must abide by God's ordinances and not those which seem convenient or reasonable to us.
Jesus' shed blood speaks better things than that of Abel. Hebrews 12:24Hebrews 12:24XWaiting for response
The shedding of Abel’s blood typified the shedding of Jesus’ blood, as the apostle wrote: “And to Jesus the mediator of the new covenant, and to the blood of sprinkling, that speaketh better things than that of Abel” Hebrews 12:24.Hebrews 12:24XWaiting for response
Verses 3-7
Genesis 4:3-7XWaiting for responseThe evil introduced by Adam and Eve’s disobedience very soon bore further fruit in their own family for their eldest son became a murderer. God had covered their nakedness with animal skins, signifying that sin could be covered by the shedding of blood in sacrifice. This, in due course, would involve the shedding of blood in the death of Jesus. The requirement on them to make animal sacrifices is implied in the record of Cain and Abel’s worship. Abel brought the firstling of his flock and God respected this because it was according to his commandment v.4.Genesis 4:4XWaiting for response Cain, however, brought the fruit of the land and was rejected by God vs.3,5.Genesis 4:3,5XWaiting for response He was therefore instructed that if he did well he would be accepted vs.6-7,Genesis 4:6-7XWaiting for response but instead of doing what God required he murdered his more righteous brother.
This scenario is re-enacted repeatedly throughout the historical record in the Bible, with the wicked slaying the righteous for envy, and the principal example of this is the murder of Jesus by the religious leaders of the Jews.