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.

Why have all been reckoned under sin?
What motive will inspire all true parents to faithfulness in teaching their children?
What power was represented by the ram having two horns?
How was the destruction of Jerusalem and the sanctuary by the Romans then foretold?
What proves that the law is an undivided whole?
What does the Psalmist say of these chariots?
How may we obtain eternal life?

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