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 was required in order to effect this reconciliation?
What did Jesus say the Spirit of truth would do?
What immediately followed this complete apostasy?
Who first enjoined Sunday-keeping by law?
Why was the parable of the importunate widow given?
15. Because Solomon asked for wisdom rather than for long life and riches, what besides wisdom did God give him?
4. And when the new heavens and the new earth have appeared, and the holy city, New Jerusalem, then he made?

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