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.

9. In what words to Peter did Jesus indicate the kind of service a converted person should render to his brethren?
What command did the Lord later give to Abraham?
How did Christ's death on the cross affect the whole sacrificial system?
What has He commanded men to observe in memory of this great work?
What reason is given in the fourth commandment for keeping the Sabbath day holy?
Why did God command Israel to hallow the Sabbath?
13. The righteous dead are raised at Christ's second coming. When will the rest of the dead, the wicked, be raised?

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