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 kind of worship results from false teaching?
What has ever been the theme of God's prophets?
How is the law further described?
What day is especially indicated as the day to prepare for the Sabbath?
What will be the experience of those who say in their hearts that the Lord is not soon coming?
How many will receive a reward when Christ comes?
What was to take place under the third trumpet?

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