Genesis 4:8

"Now Cain said to his brother Abel, 'Let's go out to the field.'  And while they were in the field, Cain attacked his brother Abel and killed him."  Genesis 4:8

The Qbible doesn't translate what Cain said to Abel.  It only says Cain talked to Abel and then when they were in the field Cain killed Abel.  Did they spend time together often?  Did Cain plan the murder of his brother before hand or was it in the heat of the moment? 

Anyone that has siblings knows how frustrating they can be, even when they're not doing anything wrong.  They're your siblings, they're suppose to think like you and understand you, right?  Unfortunately, that doesn't seem to be the case.  Even my brother, who I am the closest too, thinks differently then me about a lot of things and it can lead to some friction.

Cain let all of his anger and jealousy towards his brother control him and he killed him.   So here is the first recorded death.  Did they even realize what that was going to be like before then?  God had warned Adam and Eve about it back in Genesis 2:17 when he told them the consequences if they ate from the tree of the knowledge of good and evil, but being told about something is different then living through it and experiencing it.

Whether he fully understood what his actions would bring about or not, Cain still did an evil thing.  He ignored the warnings God had given him before and had physically attacked his brother.