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 has Christ been made for us, and for what purpose?
What testimony did the chief priests and Pharisees bear concerning Christ's work?
By what did Peter, on the day of Pentecost, say that Christ had been approved by God?
9. What expressions in the prophecy of Joel seem to imply a double fulfilment of this outpouring of the Spirit?
What did He thus abolish?
What did the apostles say to the idolaters at Lystra?
What imperial law was issued in AD. 386?

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