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.

When man first transgressed, what was done to prevent him from living for ever in sin?
What appeared unto Daniel in 538 BC., the same year in which Babylon fell?
What do the works of God declare?
What did the Savior say should precede the end?
What promise is made to those who look for Him?
What appeared upon the opening of the second seal?
How was Peter delivered later?

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