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.

With what measure of love should we serve others?
What statement testifies to Abraham's faith in God ?
What question did others raise in opposition to this view?
How intimate is His union with believers?
With what did He say they would he baptized?
11. Where did the apostle see this same company a little later, and what did they have in their foreheads?
What will finally he the privilege of God's children?

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