Genesis 4 begins with the story of Cain and Abel. The account is well known as the first murder in human history. Cain and Abel both brought offerings to God. Cain was a farmer and his offering was the fruit of his crops. Abel was a shepherd and his offering was a firstborn from his flock. God looked favorably on Abel’s offering but not on Cain’s. Cain was very angry over his rejection and in the end murdered his brother. What made Abel’s sacrifice acceptable to God?
Genesis says little about why God accepted Abel’s offering. In Genesis 4:7 God tells Cain, “if thou doest not well, sin lieth at the door.” God’s assessment of Cain’s sacrifice was that Cain did not do good, but Genesis does not tell us in what way Cain erred.
Hebrews 11 adds a little insight to Abel’s sacrifice. “By faith Abel offered a more excellent sacrifice.” The reason God accepted Abel’s sacrifice was because Abel made his offering “by faith”. The difference between Cain and Abel was faith.
Cain brought an offering to God. He obviously believed in God and believed God should be worshiped. Cain’s lack of faith was something other than doubt about the existence of God. The rest of Hebrews 11 describes faith as believing God’s Word to be true and obeying His commands. In some way Cain did not believe and obey God’s Word.
Hebrews 11:4 says that God spoke well of Abel’s gifts. This may suggest that the kind offering Abel brought was part of what made it acceptable to God. The description of Cain’s offering and Abel’s offering in Genesis 4 seems significant. Cain brought produce, Abel brought a sheep. The pattern of sacrifices found later in the Bible reveals that God required His people to offer animal sacrifices. As Hebrews 9:22 says, “without the shedding of blood there is no forgiveness.” While Genesis does not say that God commanded Cain and Abel offer animal sacrifices, maybe Cain’s sacrifice was rejected because he did not obey God’s requirements for sacrifice.
In Genesis 3:15 God promised Adam and Eve He would send a deliverer who would rescue them from the horrors of sin. Maybe Abel was accepted because he believed God’s would send a deliverer and his offering was a reflection of his faith in God’s promise.
Possibly one of these suggestions is the correct answer. Possibly a combination of both. The Bible does not give a definite answer. Some questions cannot be fully answered with all the details we would like. The Bible clearly states that Abel’s sacrifice was accepted because he offered it by faith. Even today faith is required to come to God. “But without faith it is impossible to please Him: for he that cometh to God must believe that He is, and that He is a reward of them that diligently seek Him.” (Hebrews 11:6)