A really hard question on Satan and deception.

[IATIA]

In the first place it wasn't a threat, God told them what would happen and it did. Second I would suppose that God explained to them what death was, being omniscient I do not think this would have been such a hard thing to do.

Assumptions. I say they were destined to die if they did not eat of the tree of life. As it was, they ate of the tree of knowledge at which point god banished them before they could eat of the tree of life. Your god knew this would happen, ergo the threat of death.

threat noun \ˈthret\

1. an expression of intention to inflict evil, injury, or damage
   
2. one that threatens
   
3. an indication of something impending
   

threat [θrɛt] n

1. a declaration of the intention to inflict harm, pain, or misery
   
2. an indication of imminent harm, danger, or pain
   
3. a person or thing that is regarded as dangerous or likely to inflict pain or misery
   

I disapprove of your terrible misinterpretations of scripture GC, turning god into a petty tyrant. So what? Technically speaking they didn't "bring death into the world" btw, they were cursed (I know I know it doesn't sound as nice, and we like to keep god nice, rgr).

Then please explain how death technically came into the world, you spout a lot of junk but never give any relative explanation.

Death (due to old age) is basically the accumulated break down of the overall DNA of the organism. It happens to everything. I am sure someone will come along with a more technical description for you.