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.

29. What bears witness to the genuineness of the righteousness obtained by faith, apart from the deeds of the law?
What inspired Prayer sets the standard of Christian experience?
27. According to the view of the judgment presented to Daniel, what is to be given to Christ while still before the Father?
7. What, according to Matthew's account, did Christ say were to he the signs in the sun, moon, and stars?
With what are we to comfort one another?
What encouragement is held out concerning the branches which have been broken off?
What did John see concerning this city?

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