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 are some of the attributes of God?
What exhortation is based upon Christ's love for us?
Where was Christ next taken?
What, therefore, did God do?
What New Testament injunction is given respecting marriage?
Who is it that blinds men to the gospel of Christ?
What cheering promise is made to those who endure the trials and temptations of this life?

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