Genesis 4:3, 4: Cain brought of the fruit of the ground an offering unto the Lord. And Abel, he also brought of the firstlings of his flock and the fat thereof. And the Lord had respect unto Abel and to his offering.
Recognizing that ”every good and perfect gift comes from above,” humans from very early on made sacrifices and offerings to God or to the gods. Apparently, men learned about offerings from Adam, who was taught by the Lord when He made animal skins for clothing. But the reason for the offering would differ among men.
Those who ”walked in the way of Cain [Jude 1:11]” brought a sacrifice of their own human effort and good works. Cain’s type of people wanted to please the god with their good works so that the god wouldn’t be mean to them and instead give them good things. When the god sees how good we are He rewards in kind. Most non-Christian religions end up offering to demons. Even good Christians are still tempted to ”be good” in order to gain God’s favor and blessing.
Those who emulate Abel bring the blood sacrifice of the Lamb of God, by faith in someone outside themselves. ”By faith Abel offered to God a more acceptable sacrifice than Cain, through which he was commended as righteous [Hebrews 11:4].” Abel’s type of people come to God in faith offering up the blood sacrifice of Christ, the Son of God. It is the death and merits of another (not self) that receives acceptance and offers genuine thanks.
The appropriate and acceptable human response to the lavish kindness and abundant blessing of God is faith in the the substitutionary sacrifice of the Lamb of God. Thank God, He forgives our sins, hears our prayers, and commends us as righteous because of Christ.