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.

Of whom did Christ say the Scriptures testify?
Is there salvation through any other?
What was the effect of this apostasy?
What was one principal object in calling this council?
By what name is the fifth state of the church addressed?
What is to be finished when the seventh trumpet is about to sound?
What will the Lord he to His people at this time?

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