How early was this sacrificial system known?

Answer

"By faith Abel offered unto God a more excellent sacrifice than Cain, by which he obtained witness that he
was righteous, God testifying of his gifts." Heb. 11: 4. See Gen. 4: 3-5; 8: 20.

What gave special force to the oath of an angel?
In what language did Isaiah foretell Christ's birth?
What did Moses set forth as the basis of righteousness?
How are the rise and work of this power described?
What similar charge was brought against the Apostle Paul?
What is one evidence that one has a knowledge of God?
What will then he the condition of all the earth?

Questions & Answers are from the book Bible Readings for the Home Circle