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.

How many are affected by Adam's transgression ?
What instruction shows that sanctification is a progressive work?
What is the mark of a true friend?
Does God design that His great work of creating the heavens and the earth shall be remembered?
Against what deceptions did Christ then warn us?
At His ascension, how did the angels say Christ would come again?
When Peter was imprisoned and about to be executed by Herod, what did the church do?

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