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 should all Christian parents bring up their children?
In the judgment-hour message, whom are all called upon to fear, glorify, and worship?
Why, under these plagues, does the Lord give men blood to drink?
What announcement is made under the seventh plague?
What is charity called?
What is one good evidence of genuine repentance?
For what did Abraham look?

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