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 ordinance is closely associated with believing the gospel ?
On what basis is there no possibility of justification for the sinner?
Wherever Abraham went, what was his practice?
When and by whom was the Sabbath made?
How was the faithfulness of this church commended?
How many of these beings did John see around the throne?
When will immortality be conferred upon the saints?

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