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.

How were the Scriptures given?
What would make the death of Christ in vain?
How is such a baptism described?
How will such a mother he regarded?
What requirement was made by these teachers from Judea concerning the ceremonial law?
What power mentioned in the thirteenth chapter of Revelation is to enforce this mark?
Is this chastening a pleasant experience?

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