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.

Upon what basis is justification granted?
What does Christ as the advocate of His people confess before the Father and His angels?
12. Are men's hearts now \"failing them for fear, and for looking after those things which are coming on the earth\"?
When will the resurrection of the just occur?
Does God delight to afflict any?
In whom are we complete?
What does Daniel say of this kingdom?

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