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 beautiful picture of home life is drawn by the Psalmist for the father who fears the Lord?
What has ever been the theme of God's prophets?
What announcement immediately follows the judgment-hour message of Rev. 14: 6,7?
What reason is assigned for the fall of Babylon?
18. Before giving the law at Sinai, what did God say because some of the people went out to gather manna on the seventh day?
By what are all men to be finally judged?
When Paul wished to preach the true God to the idolatrous Athenians, how did he describe Him?

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