Beginning of the End - Ellen G. White

The warning given to our first parents--"In the day that you eat
of it you shall surely die"--did not mean that they were to die on the
very day they ate the forbidden fruit. But on that day the irreversible
sentence would be pronounced, and on that very day they would be
doomed to death.
In order to have endless existence, a person must continue to
eat from the tree of life. Deprived of this, the vitality would
gradually diminish until life would become extinct. It was Satan's
plan that Adam and Eve would eat of the tree of life and thus
prolong an existence of sin and misery. But holy angels were
commissioned to guard the tree of life. Around these angels flashed
the appearance of a glittering sword. No one from the family of
Adam was permitted to pass that barrier; this is why there are no
immortal sinners.
Is God Too Severe?
Most people regard the tide of misery that flowed from the
transgression of our first parents as too awful a consequence for so
small a sin. But if they would look more deeply into this question,
they might recognize their mistake. In His great mercy God did not
give Adam a severe test. The very lightness of the prohibition made
the sin exceedingly great. If some great test had been given to
Adam, then those whose hearts incline to evil would have excused
themselves by saying, "This is a trivial matter, and God is not so
particular about little things."
26