Genesis 2:17

But of the tree of the knowledge of good and evil, thou shalt not eat of it: for in the day that thou eatest thereof thou shalt surely die.

1. After telling the man he could eat of any tree in the garden, the LORD God told him not to eat of the tree of the knowledge of good and evil.
2. Eating the fruit of the tree of the knowledge of good and evil would eventually cause the man to die.
3. Since Adam lived 930 years after he ate from the tree of the knowledge of good and evil, it is apparent that when the LORD God said man would die "in the day that thou eatest thereof" He was not referring to an earth day. This suggests the possibility that God's work days during which He created the earth were not equivalent to what we call a day, or 24 hours, today.
4. The man was apparently innocent at this point, not understanding the difference between good and evil.
5. The man was apparently immortal at this point. Only by eating of the tree of the knowledge of good and evil would he become mortal.