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.

In connection with Christian baptism, what is washed away?
By what is this cleansing from sin and fitting for God's service accomplished?
What divine purpose was wrought out in the sufferings of Christ?
14. What instruction did Abraham give his servant Eliezer when sending him to select a wife for his son Isaac?
Where was the law of God written under the old covenant?
What day is the Sabbath, \"according to the commandment\"?
How may we obtain eternal life?

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