Final answer:
Cain killed Abel due to anger and jealousy because God favored Abel's offering over Cain's, leading to the first murder in the Bible.
Step-by-step explanation:
Reason Behind Cain's Murder of Abel
From the Genesis passage, the reader may infer that the reason why Cain killed Abel was anger that the Lord favored Abel's offering over his own. According to Genesis 4:2-8, Cain's reaction to God's preference for Abel's sacrifice leads to the very first murder recorded in the Bible. The passage suggests that Cain's jealousy and frustration culminated in the violent act against his brother.
This act of violence was driven by Cain's displeasure and inability to cope with the Lord's approval of Abel's offering while his was rejected. It is a story that speaks volumes about human emotions and the dangers of letting negative feelings like envy and anger go unchecked.