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?
What is God's love able to do for His children?
How is faith brought to perfection?
Upon what ground were the previous promises then renewed to Abraham?
Why were many attracted to Christ?
What was the date of Constantine's famous Sunday law?
What does He indicate as one of its purposes?

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