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 other statement did He teach the same truth?
To whom did God commit the care and early training of His only begotten Son?
14. How was the sanctuary itself to be cleansed, and how were the sins of the people to be finally disposed of?
By what method of reasoning did Christ justify acts of mercy on the Sabbath day?
16. After the sealing work brought to view in Revelation 7, which takes place under the sixth seal, how is the seventh seal introduced?
How suddenly will the plagues come upon modern Babylon?
Whom will they be like?

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