Why was Cain's sacrifice unacceptable?
Cain offered God an unacceptable sacrifice, but Abel offered an acceptable one.
. . . And Abel was a keeper of flocks, but Cain was a tiller of the ground. So it came about in the course of time that Cain brought an offering to the LORD of the fruit of the ground. And 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; but for Cain and for his offering He had no regard. So Cain became very angry and his countenance fell. (NASB) Genesis 4:2-5
Both men presented an offering to God. One offered plants from the ground and the other offered animals. Contrary to the teaching and preaching of many, this is not the reason for God’s unhappiness with Cain. The original Hebrew language makes a strong statement that Abel not only offered “firstlings” or the first born from his flocks, but he offered the best – “their fat portions.” Abel offered before he knew there would be any more, and he offered the best of the firstlings.
The Acceptable Sacrifice. Why did Abel’s gift please God?
By faith Abel offered to God a better sacrifice than Cain, through which he obtained the testimony that he was righteous, God testifying about his gifts, and through faith, though he is dead, he still speaks. (NASB) Hebrews 11:4
Abel’s sacrifice was the result of faith in God. Abel lived by faith. He trusted God. We are not told if his faith included the birth of Jesus, His death and His return to life. What we do know is that Abel trusted God. He must have highly respected God for he gave first and his best. He put God first. His gifts were the proof of a true heart. Abel sacrificed as a result of his faith in and walk with God.
The Unacceptable Sacrifice. Hebrews 11:4 helps us see Abel’s gift through God’s eyes and Proverbs 15:8 helps us see Cain’s gift.
The sacrifice of the wicked is an abomination to the LORD, But the prayer of the upright is His delight. (NASB) Proverbs 15:8
Cain served God – a little bit. He gave God gifts. Since when do unbelievers not seek to offer gifts to God? He offered gifts, but they were rejected – rejected because his heart was wicked – rejected because he threw God a “little gift” to make Him happy. He did not respect God nor value Him. God desires to be first in our life. He wants us to believe Him – to trust Him. Cain’s actions proved that he was not living by faith. Why was Cain’s sacrifice unacceptable? He did not live by faith – trusting God!
Every Christian, some more than other – at some point in our walk offer God “vegetables” from our garden. It is easy for us to give God gifts and then forget what He really wanted was a loving, longing, hungry heart that desires Him. A heart that is willing to give to Him whatever He wants – the best – all you have – yourself!
I urge you therefore, brethren, by the mercies of God, to present your bodies a living and holy sacrifice, acceptable to God, which is your spiritual service of worship. And do not be conformed to this world, but be transformed by the renewing of your mind, that you may prove what the will of God is, that which is good and acceptable and perfect. (NASB) Romans 12:1-2
Jesus wants our heart and our trust.