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.

Upon what ground does God's work for sinners rest?
What was offered Christ at His crucifixion?
Who took charge of Christ's body after it was taken down from the cross?
How is the conflict between Christ and Satan described?
In what condition is man while in the grave?
How does God regard sorcerers?
What will follow this great conflagration?

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