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.

13. What did John the Baptist say to the Pharisees and Sadducees when he saw them come to his baptism?
What threefold union is thus established?
When Christ ascended, what did He give to men?
Of what is the Sabbath commandment a part?
What has been one great characteristic of the Papacy?
What will be the fifth plague?
What incentive have Christians for doing prison work?

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