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 place has the will in determining whether man shall have life?
How did Noah show his faith in this message?
How many were saved in the ark?
How had Christ's teaching by parables been foretold?
What should be the prayer of every parent?
What final disposition was made of the sins of the people?
What are we admonished not to do?

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