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 necessary in order that the preaching of the gospel may be profitable?
What reply did Christ make?
By what other terms are these covenants designated?
At His ascension, what assurance was given of Christs return ?
What wonderful demonstration will accompany the Lord's coming?
What name is given to the second state of the church?
What will the Lord he to His people at this time?

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