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 is said of the tender compassion of God?
What three essentials for a Saviour are found in Christ?
Why was further instruction concerning this vision necessary ?
What is the purpose of the Federal Council of the Churches of Christ in America?
16. What action of the American Federation of Catholic Societies indicates that Catholics will gladly \"join hands\" with Protestants in enforcing Sunday observance by law?
What warning has Christ given concerning false views of the manner of His coming?
What false idea of this gathering were some to hold?

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