Genesis chapter four describes the very first sacrifice that mankind offered to God. Adam and Eve, the first ancestors of mankind, were driven out of the Garden of Eden after sinning against God, and they gave birth to two children, one named Cain and the other Abel. Eventually, these two sons came to have occupations, and one became a farmer, while the other became a shepherd.
It then came to pass that these two men brought offerings to God. Cain, a farmer, brought the fruit of the ground as his offering, while Abel, a stockman, sacrificed the firstborn of the flock and their fat as his offering to God. However, while God accepted Abel’s offering, He rejected Cain’s offering. As a result, the Bible says that Cain got very angry and his countenance fell.