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 the true basis of the brotherhood of man?
Can we close our ears to truth, and remain innocent before God?
To whom did Christ become the author of salvation?
For what purpose did Christ come to this world?
3. What urgent petition of the prophet connects this prayer with the vision of the taking away of the continual mediation and the desolation of the sanctuary recorded in Daniel 8?
What is the wages of sin?
Who made the Sabbath?

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