Gen. 3:4-5  "And the serpent said unto the woman,  Ye shall not surely die:  For God doth know that in the day ye eat thereof, then your eyes shall be opened and ye shall be as gods, knowing good and evil."

Half truths:  The evil one spoke in half truths.  Give someone a truth to cover up a lie.

1.  "Ye shall not surely die."  Death came.   They lost access to the Tree of Life.

2.  "I know what God thinks and knows."  The serpent knew one thing.  That the tree was forbidden.

3.  "On the very day you eat, your eyes will be opened. "  Opening your eyes, meant that the serpent knew something that God didn't.  God said nothing about "Opening your eyes".        

4.  "You will be like gods, knowing good and evil."  There is one God.  Mankind will never be like God.

The devil, satan, evil one, always tells half truths that lead you astray if you listen.  Sin sounds good.  Looks good.  May even be very satisfying in the moment.  But later...there is a payoff.

In Romans 3:6, we find that, "The wages of sin is death."  Wages were not gold or money.  The people Paul was writing to all knew what a wage was.   It was a script of some sort that, for instance, Roman solders were paid with.  When they went back to Rome they could turn the script in for money.  You couldn't spend script.

Script was something that paid off "later".  In other words, the pay off "later" (the wage of sin) was death.  The pay off later of sin is eternal death.