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.

Through whom are we reconciled to God?
With what words do the Scriptures conclude the record of Christ's early life?
When used with reference to prophecy, what does the word fulfil mean?
1. According to the words of the angel to Daniel, when might the world look for an increase of knowledge?
In what condition is man while in the grave?
Are they interested in the conversion of men?
Whose prayers does Solomon say are an abomination?

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