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 did Isaiah say Christ would do with the law?
How extensively is this message to he proclaimed?
How may we know that we love the children of God?
With what words did He justify acts of mercy on the Sabbath day?
In ministering to the needy, whom are we really serving?
In what one promise are all these promises summed up?
In narrating the work of creation, what statement is made concerning its completion?

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