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 is said of God's faithfulness in keeping His promises ?
What did the people say when they saw these things?
What restriction did God make respecting marriages in Israel?
Against what are husbands cautioned?
How did Jesus show His loyalty to God?
How many will yield to the demand to worship the beast?
How many distinct classes will have a resurrection?

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