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 use of this prophecy by the Apostle Peter shows that it referred to Christ?
How may we determine the truthfulness of any doctrine ?
Of whom was Christ to be born?
Of what were the different parts of the image composed?
What was Satan's design in thus persecuting the church?
What special miracle is finally to be performed to deceive men, and fasten them in deception?
Hearing these words, what questions did the disciples ask?

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