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.

How great. is Gods love for the world?
How is the love of God supplied to the believer?
How many may receive this gift?
What enabled Abraham to endure the test?
What Christian ordinance has been given as a memorial of Christ's burial and resurrection?
Where will Christ then take His people?
What did the Ephesians do upon hearing the gospel?

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