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.

Were the gifts of the Spirit to continue forever?
What do the works of God declare?
6. How did they manifest their displeasure at His healing the man with the withered hand on the Sabbath?
How early was this tendency manifested?
11. What sign did Christ mention by which His disciples might know when the destruction of Jerusalem was near?
How many will see Him when He comes?
How numerous are these wicked spirits, or fallen angels?

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