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.

With whom are the children of God joint heirs?
Through whom are we reconciled to God?
What is the basis of faith?
What restriction did God make respecting marriages in Israel?
How extensively is this message to he proclaimed?
19. Just before the pouring out of the plagues, what call does God send to His people still in Babylon?
6. What would have been the result to the dead had not Christ procured their release from the grave?

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