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.

How did Christ make it clear to them that the Scriptures testify of Him?
Does the Bible recognize what may be called \"present truth\"?
When will the gifts of the Spirit he no longer needed?
How important is it that we know God?
What did Christ say of worship based upon the commandments of men?
13. The righteous dead are raised at Christ's second coming. When will the rest of the dead, the wicked, be raised?
Whatever may come, what blessed assurance has everyone who loves God?

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