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.

And what besides a mere belief in the truth is necessary?
How has God revealed to us the hidden things of the kingdom?
What reward in this life is promised the faithful mother?
Where was Daniel at this time?
What illustration of this is given in the Bible?
How does the Lord, through the prophet Isaiah, indicate what is true Sabbath-keeping?
Who will be permitted to enter it?

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