It is evident that the Bible does not record all that was communicated to man; however, the careful student sees that sacrificial worship was a Divine revelation. The statements that Cain brought and Abel brought their respective sacrifices, may indicate that there was a specific time and place where offerings were presented to God (Genesis 4:1-4). In addition to this, we learn that Abel offered his sacrifice by faith, (Hebrews 11:4), and that faith comes by hearing the word of God (Romans 10:17); that Cain sinned (Genesis 4:7); and that sin is the transgression of the law (1 John 3:4).