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.

In whom is the gift?
What high ideal should he placed before the young?
What was done with the blood of the offering?
What illustration of this is given in the Bible?
What is predicted of the moral condition of the world in the last days?
What cheering promise is made to those who endure the trials and temptations of this life?
Why does God comfort us in tribulation?

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