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.

In what words is His impartiality proclaimed?
What does the sorrow of the world do?
What statement did Paul make concerning his faith and manner of worship?
8. Did God bless and sanctify the seventh day while He was resting upon it, or when His rest on that day was past?
What, according to prophecy, was to be Christ's attitude toward the law?
What does Neander say of the securing of these laws?
How may we obtain eternal life?

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