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 accompanies repentance?
What is felt in heaven when a sinner repents?
Who is the Comforter, and what was He to do?
What peaceful, happy conditions will prevail in the next world as compared with those of this life?
What did God purpose to do with the people of that day?
For what did Christ reprove the Pharisees and Sadducees?
For what did Job say he would wait after death?

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