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 is the great purpose of Christ in His work of reconciliation?
What will result if correction is withheld?
How are the rise and work of this power described?
When did the priest minister in the first apartment of the sanctuary?
Why do the inhabitants of heaven worship God?
What is the love of God?
What shows that the angels sent to Abraham and Lot were real beings?

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