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.

What classes of persons are necessarily shut out of the kingdom of God?
What was the result of this great miracle?
Whom does Christ say He came to call to repentance?
Because evil is not punished immediately, what presumptuous course do many pursue?
How did Christ answer him?
18. Knowing that the unbelieving Jews would still cling to their false ideas respecting the Sabbath, pray?
What were the colour and character of the fourth symbol?

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