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.

Upon what ground were the previous promises then renewed to Abraham?
18. In what statement was Christ promised as a Savior and Deliverer of the race as soon as sin entered?
6. In His reply, how did Christ indicate that neither the end of the world nor of the Jewish nation was immediately at hand ?
When did the moon refuse to give her light?
By what name is the fifth state of the church addressed?
How does Joel describe the day of the Lord?
21. What scripture shows that Satan is to work with special power and deceptive wonders just before Christ's second coming?

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