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 accompanies repentance?
What classes of persons are necessarily shut out of the kingdom of God?
Did Joshua think it immaterial what god Israel served?
22. In what announcement in the New Testament is the establishment of the kingdom of God made known?
What complaint is made against Sunday trains and Sunday newspapers?
13. At the instance of church bishops, what still further law was secured under Theodosius the Younger, in 425?
What promise did Christ make concerning His coming?

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