The next time we hear anything about a sacrifice it involves Adam’s two sons. Gen 4:2-5: “Now Abel was a keeper of sheep, but Cain was a tiller of the ground. And in the process of time it came to pass that Cain brought an offering of the fruit of the ground to the LORD. Abel also brought of the firstborn of his flock and of their fat. And the LORD respected Abel and his offering, but He did not respect Cain and his offering. And Cain was very angry, and his countenance fell.”

Literally: at the end of days, which denotes that a period of time had lapsed – at a certain time of the year they approached God with an offering, a sacrifice. Adam probably told these things over and over in his family circle and it became oral tradition, and took on a fixed form until it was written down. We know this because when it was time for Cain and Abel to present their sacrifice they knew what to bring - an animal. History indicates that animal sacrifices are taught in nearly all ancient cultures.

God had ordained the means of how man will approach Him in his sinful condition. The implication is that they were taught to continually sacrifice for sin. We can assume that Adam and Eve would have passed it on to their children Cain and Abel.

Cain disobeyed the divine arrangement God gave Adam by offering his own hands work than the sacrifice of blood. His was a vegetable offering, the other an animal. One offering was without life; the other was a sacrifice of life.  It was rejected by God because it was in disobedience to the Lord’s instructions, and was faithless. the blood sacrifice pointed to Christ, as the last sacrifice.

What brought Cain to kill his brother? It was his failure to obey God. The first murder was prompted by jealousy, V. 8-10 Now Cain talked with Abel his brother; and it came to pass, when they were in the field, that Cain rose up against Abel his brother and killed him. Then the LORD said to Cain, "Where is Abel your brother?" He said, "I do not know. Am I my brother's keeper?" And He said, "What have you done? The voice of your brother's blood cries out to Me from the ground.”

 The way of Cain is man’s way and is the basis of every false religion in history. Man, since the fall, has been trying to find another way instead of doing it God’s way

He was angered that his offering was not accepted, and that his brother’s was, and he could not stand the rejection. He took it personally because it was the work of his own hands. I Jn. 3:12 tells us ‘Cain who was of the wicked one and murdered his brother. And why did he murder him? ‘Because his works were evil and his brother’s righteous.’

Cain murdered his brother because he gave a better sacrifice. Heb. 11:4: “By faith Abel offered to God a more excellent sacrifice than Cain, through which he obtained witness that he was righteous, God testifying of his gifts; and through it he being dead still speaks.”

God testified of Abel being righteous because he obeyed the divine command, God consistently calls those who bring a sacrifice with blood as being righteous.

Two key words are used: Sacrifice: Heb. thusia- a sacrifice, victim; Gifts- doron - a present; specially, a sacrifice (Strong’s Concordance). How does Abel’s gift through it he being dead still speaks.”

Later in Heb. 12:24 the author speaks “to Jesus the Mediator of the new covenant, and to the blood of sprinkling that speaks better things than that of Abel.”

Here the author is comparing the blood Abel gave in sacrifice and Christ being superior because He was sacrificed for us.

I Jn. 3:11-12 “For this is the message that you heard from the beginning, that we should love one another, not as Cain who was of the wicked one and murdered his brother. And why did he murder him? Because his works were evil and his brother's righteous.”

The story of these two sons is concentrated on the time of the sacrifice. It shows that we cannot give what we think is best to God, we can’t meet His standards by our good deeds or by the work of our own hands, we are to trust in the lamb who gave his life for us.