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 revealed in the gospel?
What kind of worship results from false teaching?
Who appeared to accuse Christ before Herod?
With what words did Daniel begin the interpretation of the dream?
How, then, did the Lord prove the people (verse 4) whether they would keep His law, or not?
26. When Israel had apostatized, and were almost universally worshipping Baal, what appeal did Elijah make to them?
What promise is made to them that walk uprightly?

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