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.

To what extent has Christ suffered for sinners?
What is necessary in order that the preaching of the gospel may be profitable?
Of what is the Sabbath commandment a part?
When tempted to bow down and worship Satan, what reply did Christ make?
How is the closing period of tribulation of the church during this time referred to?
But are not the righteous dead in heaven?
17. What great contrast will be seen between the present body and the one to be put on in the resurrection?

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