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.

From what time has the devil been a murderer?
What is the last book of the Bible called?
What relation does the earthly sanctuary sustain to the heavenly?
How suddenly will the plagues come upon modern Babylon?
How long will they live?
In what respect is the reaping of God's people to differ from their sowing?
What will flow through the city?

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