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.

In what language did Isaiah foretell Christ's birth?
How only do any become children of God?
Did Joshua think it immaterial what god Israel served?
18. What is said of those who live to see the deliverance from modern Babylon, and the restoration of the true gospel?
When had God said this?
Of what did Christ say the Son of man is Lord?
What will follow this great conflagration?

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