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 are His mercies continually manifested?
Of what is Christian baptism an evidence?
When brought before the king, what did Daniel say?
What time intervenes between the two resurrections?
Where are the Ten Commandments recorded?
How may we be freed from the guilt of our sins, or our transgressions of God's law?
How ancient is this doctrine of Christ's coming?

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