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.

Into what condition has sin brought the entire creation?
When man first transgressed, what was done to prevent him from living for ever in sin?
Why were many attracted to Christ?
What positive assurance of the resurrection is given?
Wherever Abraham went, what was his practice?
When did Paul expect to receive his crown?
How much does one know of God when dead?

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