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 is the true basis of the brotherhood of man?
19. What message did Christ send to John the Baptist while John was in prison, to strengthen his wavering faith?
What promise is thus fulfilled?
How much honor is due to Christ?
What special miracle is finally to be performed to deceive men, and fasten them in deception?
What was one principal object in calling this council?
Who gives men the power to get wealth?

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