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 blessed experience follows upon the acceptance of Christ as our righteousness?
How is the character of the law described by the Apostle Paul?
What is the love of God declared to be?
What did God do in the beginning on the seventh day?
What were these locusts said to have over them?
When afflicted, for what did he pray?
To whom did Jesus first send the twelve disciples?

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