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 are the wages of sin?
When did Sin and death enter the world?
How long was the Sabbath to be a sign of the true God?
What was Job's confidence concerning Christ's coming?
How did Christ speak of the gathering of the Gentiles?
How willing is God to hear and answer prayer?
Who has everlasting life?

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