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 was required in order to effect this reconciliation?
What assurance has the believer of his union with God?
17. What similar language is used by the Apostle Paul in describing the \"mystery of iniquity,\" or \"man of sin\"?
How often will they congregate to worship the Lord?
What did God do in the beginning on the seventh day?
Are the righteous freed from afflictions in this world?
How may we obtain eternal life?

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