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 has Christ been made for us, and for what purpose?
For what are His parables noted?
What words of Peter seem to indicate another outpouring of the Spirit?
Did Christ keep the Sabbath?
What directions were given by Constantine's Sunday law of March 7, 321?
What has been promised in order that man may be redeemed from this condition?
How may grace and peace be multiplied in believers?

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