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 condition is faith reckoned for righteousness?
To what knowledge would God have all men come?
What did the prophet say His name should be called?
What great truth therefore follows?
10. After the fall, what sort of marriages were introduced by men, which were productive of great evil?
What appeared unto Daniel in 538 BC., the same year in which Babylon fell?
While drinking the wine, what gods did they honor?

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