That is, sad to say, because your view is irrational.
No, on a number of points. First off, sin of man did not originate death.
1 Corinthians 15:21-22 (NASB) 21 For since by a man came death, by a man also came the resurrection of the dead. 22 For as in Adam all die, so also in Christ all will be made alive.
Notice it doesn’t say “as in Adam all sin”... but rather by man came death... and in Adam all die.
Secondly, the fall of man did make sin a cause of death, making death the enemy.
Romans 5:17 (NASB) For if by the transgression of the one, death reigned through the one, much more those who receive the abundance of grace and of the gift of righteousness will reign in life through the One, Jesus Christ.
18 So then as through one transgression there resulted condemnation to all men, even so through one act of righteousness there resulted justification of life to all men.
God does not lie and yes, God does speak of things that are not yet.
Like He did when He told Adam that dying he would die if he ate from the tree of the knowledge of good and evil.
Genesis 3:22 (NASB) Then the LORD God said, "Behold, the man has become like one of Us, knowing good and evil; and now, he might stretch out his hand, and take also from the tree of life, and eat, and live forever"--
By your logic, Adam must have known good & evil prior to the fall because God tells him not to eat from the tree of the knowledge of good & evil or dying he would die... yet here we see that the knowledge of good & evil resulted from the sin. And indeed we see they didn’t know they were naked until they sinned. How can half the sentence be a lie? It cannot.
Do you understand why God cannot lie? Probably not since you don’t appear to take Genesis as true.
Genesis 1 is the reason it is impossible for God to lie. Reality itself conforms to God’s lies... He said “let there be light” when there was no light, and then suddenly there was light. There is so much power in His Word, if God lies, reality conforms to make it truth. Therefore it is literally impossible for God to lie.