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.

When man first transgressed, what was done to prevent him from living for ever in sin?
9. In what words to Peter did Jesus indicate the kind of service a converted person should render to his brethren?
What are the evidences that one has been born of God?
What reason did they give for not receiving Him?
How did Christ say those who rejected Him reasoned?
What besides creation were Israel to remember when they kept the Sabbath?
What is said of those embraced in the first resurrection?

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