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.

How fully did Israel once acknowledge their wrong doing ?
What are the commandments of God declared to be?
When will the gifts of the Spirit he no longer needed?
What, therefore, did God say He would make?
How many must meet the test of the judgment?
What promise has God made to bereaved mothers?
In how many things may we ask help from God?

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